U.S. patent application number 14/379494 was filed with the patent office on 2015-01-29 for uses of ided nanostructures in nucleic acid technology.
The applicant listed for this patent is NVIGEN, INC.. Invention is credited to Aihua Fu, James Zhu.
Application Number | 20150031575 14/379494 |
Document ID | / |
Family ID | 48984837 |
Filed Date | 2015-01-29 |
United States Patent
Application |
20150031575 |
Kind Code |
A1 |
Fu; Aihua ; et al. |
January 29, 2015 |
USES OF IDED NANOSTRUCTURES IN NUCLEIC ACID TECHNOLOGY
Abstract
The present invention relates to compositions comprising a
porous nanostructure of a known characteristics and a fragment of
nucleic acid having a known sequence. Methods of use of the
compositions were also provided, for example in DNA amplification,
detection, and DNA sequencing.
Inventors: |
Fu; Aihua; (Sunnyvale,
CA) ; Zhu; James; (Cupertino, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NVIGEN, INC. |
Sunnyvale |
CA |
US |
|
|
Family ID: |
48984837 |
Appl. No.: |
14/379494 |
Filed: |
February 19, 2013 |
PCT Filed: |
February 19, 2013 |
PCT NO: |
PCT/US13/26758 |
371 Date: |
August 19, 2014 |
Current U.S.
Class: |
506/9 ; 435/6.11;
536/24.3; 536/24.33 |
Current CPC
Class: |
C12Q 1/6876 20130101;
C12Q 1/6869 20130101; G01N 21/6428 20130101; B82Y 15/00 20130101;
C12Q 1/6869 20130101; C12Q 2565/631 20130101; C12Q 2563/157
20130101; C12Q 2563/185 20130101 |
Class at
Publication: |
506/9 ;
536/24.33; 536/24.3; 435/6.11 |
International
Class: |
C12Q 1/68 20060101
C12Q001/68 |
Claims
1. A composition comprising a first IDed porous nanostructure and a
first nucleic acid, wherein the first nucleic acid is associated
with the first IDed porous nanostructure.
2. The composition of claim 1, wherein the first nucleic acid is a
primer, a probe or a fragment of DNA.
3. The composition of claim 1, further comprising a magnetic
particle, wherein the magnetic particle is associated with one end
of the first nucleic acid and the first IDed porous nanostructure
is associated with the opposite end of the first nucleic acid.
4. The composition of claim 1, wherein the first IDed porous
nanostructure is magnetic.
5. The composition of claim 1, further comprising a second IDed
porous nanostructure and a second nucleic acid, wherein the second
nucleic acid is associated with the second IDed porous
nanostructure, and wherein the second IDed nanostructure is not the
first nanostructure.
6. The composition of claim 5, wherein the second nanostructure is
magnetic.
7. (canceled)
8. The composition of claim 5, wherein the second nucleic acid
complements to the first nucleic acid.
9. The composition of claim 5, further comprising a third IDed
porous structure, wherein the third IDed porous nanostructure is
associated with a third nucleic acid, wherein the third nucleic
acid complements to the first or second nucleic acids.
10. The composition of claim 9, wherein the third IDed porous
nanostructure is magnetic.
11. A method of detecting a condition in a sample or a subject,
comprising: hybridizing a DNA fragment from the sample or the
subject with the composition of claim 1, and detecting the presence
of double stranded DNA in the first IDed porous nanostructure which
indicates the presence of the condition in the sample or
subject.
12. The method of claim 11, wherein the first nucleic acid
comprises a known mutation associated with the condition.
13. The method of claim 11, further comprising treating the
hybridization product with a single stranded DNA endonuclease,
before detecting the presence of double stranded DNA.
14. The method of claim 11, wherein the detecting step comprises
treating the hybridization product with a double stranded DNA
dye.
15. A method of detecting a condition in a sample or a subject,
comprising: hybridizing a DNA fragment from the sample or the
subject with the composition of claim 3 in a solution; adding a
single-stranded endonuclease into the solution; subjecting the
solution to a magnetic field; and detecting the presence of a
coding signal of the first IDed porous nanostructure which
indicates the presence of the condition in the sample or
subject.
16. The method of claim 15, wherein the first nucleic acid in the
composition comprises a known mutation associated with the
condition.
17. A method of detecting the coding signals of a plurality of IDed
nanostructures in a solution simultaneously, comprising passing a
light from a solution comprising a plurality of IDed nanostructures
through a microlens array to a photosensor array; and processing
the light data to identify each IDed nanostructure in the
solution.
18. A method of detecting the coding signals of a plurality of IDed
nanostructures on a surface, comprising: assembling the plurality
of IDed nanostructures from a solution onto the surface.
19. The method of claim 18, wherein the assembling is based on
chemical interaction.
20. The method of claim 18, wherein the assembling is based on
magnetic interaction.
21. The method of claim 20, wherein the IDed nanostructures of the
composition are assembled in an ordered array format in the
presence of an applied magnetic field.
22-25. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of U.S.
Provisional Patent Application No. 61/600,699, filed on Feb. 19,
2012, which is incorporated herein by reference in its
entirety.
FIELD OF THE INVENTION
[0002] The present invention is in the field of nucleic acid
detection and sequencing.
BACKGROUND
[0003] Current DNA detection and sequencing technologies are based
primarily on placing DNA targets on substrates such as grids or
arrays so that the identities of DNAs are recognized through their
location on the substrates. Even in the cases that nanoballs are
used in DNA sequencing, these nanoballs are used as carriers for
DNA amplification and the amplified DNAs along with nanoballs are
still placed on patterned substrates.
[0004] Therefore, there are needs in the field to continue to
develop new ways for DNA amplification and detection without the
necessity of or dependence on substrate. Further, current
technology often depends on a limited number of differentiable
signals for DNA sequencing, for example, only utilizing 4 different
fluorescent colors to code the 4 individual nucleotides, such as in
Illumina's sequence by synthesis technology, and in Pacific
Biosciences' SMRT technology. Sometimes, the detection signal is
only based on one type of signal, for example, the chemiluminescent
signal from the pyrosequencing of 454 sequencing technology. These
existing technologies only sequence DNA one base by one base,
including when the electronic signal is utilized as in the nanopore
based sequencing and when the pH change is utilized as in the ion
torrent technology. Hence, a method to enable DNA sequencing
through longer base steps could be highly beneficial to improve
sequencing accuracy, reduce sequencing time, reduce cost, and
increase throughput.
SUMMARY OF THE INVENTION
[0005] One aspect of the present invention related to compositions
comprising a porous nanostructure of a known characteristics and a
fragment of nucleic acid having a known sequence.
[0006] In certain embodiments, the porous nanostructures have been
disclosed in U.S. Prov. Appl. 61/589, 777 (all references cited in
the present disclosure are incorporated herein in their entirety).
In certain embodiments, the nanostructure comprises at least one
core nanoparticle embedded in or coated with a low density porous
3-D structure or coating, which is capable of carrying or
associating with at least one payload within or on the surface of
the nanostructure.
[0007] In certain embodiments, the core nanoparticle comprises a
nanoparticle or a cluster of nanoparticles. A single core
nanoparticle may comprise a plurality or a cluster of
mini-nanoparticles. The nanoparticles in the cluster may be made by
the same composition, or different compositions.
[0008] In certain embodiments, the core nanoparticle includes, for
example, a superparamagnetic iron oxide (SPIO) nanoparticle, or a
non-SPIO nanoparticle. The non-SPIO nanparticles include, for
example, metallic nanoparticles (e.g., gold or silver
nanoparticles), a metal oxide nanoparticle, semiconductor
nanoparticle (e.g., quantum dots with individual or multiple
components such as CdSe/ZnS, doped heavy metal free quantum dots or
other semiconductor quantum dots); polymeric nanoparticles (e.g.,
particles made of one or a combination of PLGA
(poly(lactic-co-glycolic acid), PCL (polycaprolactone), PEG (poly
ethylene glycol) or other polymers); siliceous nanoparticles; and
non-SPIO magnetic nanoparticles (e.g., MnFe2O4, SAF, and other
types of magnetic nanoparticles). The core nanoparticle has a
diameter ranging from about 1 nm to about 900 nm (preferable 1-50
nm, 2-40 nm, 5-20 nm, 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8
nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm,
18 nm, 19 nm, 20 nm in size).
[0009] In certain embodiments, the core nanoparticle has a shape of
sphere, rod, tetrapod, pyramidal, multi-armed, nanotube, nanowire,
nanofiber, or nanoplate.
[0010] In certain embodiments, the low density, porous 3-D
structure refers to a structure with density at least 10s times
(e.g. 10s times, 20s times, 30s times, 50s times, 70s times, 100s
times, 1000s times, 10,000 times) lower than existing mesoporous
materials (e.g. mesoporous materials having a pore size ranging
from 2 nm to 50 nm). In certain embodiments, the low density,
porous 3-D structure has a density of <1.0 g/cc (e.g. from 0.01
mg/cc to 1000 mg/cc). In certain embodiments, the density is
determined using dry mass of the 3-D structure divided by the total
volume of such 3-D structure in an aqueous solution.
[0011] In certain embodiments, the low density, porous 3-D
structure is highly porous. Such low density structure further
refers to a structure having at least 40% to at least 99.9%
(preferably 50% to 99.9%) of empty space or porosity in the
structure. In certain embodiments, at least 80% of the pores having
size of 1 nm to 500 nm in pore radius.
[0012] In certain embodiments, the low density, porous 3-D
structure is a structure that can not be obviously observed or
substantially invisible under transmission electron microscope, for
example, even when the feature size of the low density structure is
in the 10s or 100s nanometer range.
[0013] In certain embodiments, the low density, porous 3-D
structure is made of silicon-containing molecules (e.g., silanes,
organosilanes, alkoxysilanes, silicates and derivatives thereof).
For example, the silicon-containing molecules can be
amino-propyl-trimethoxysilane, mercapto-propyl-trimethoxysilane,
carboxyl-propyl-trimethoxysilane, amino-propyl-triethoxysilane,
mercapto-propyl-triethoxysilane, carboxyl-propyl-triethoxysilane,
Bis-[3-(triethoxysilyl)propyl]-tetrasulfide,
Bis-[3-(triethoxysilyl)propyl]-disulfide,
aminopropyltriethoxysilane, N-2-(aminoethyl)-3-amino
propyltrimethoxysilane, Vinyltrimethoxysilane,
Vinyl-tris(2-methoxyethoxy) silane, 3-methacryloxypropyltrimethoxy
silane, 2-(3,4-epoxycyclohexy)-ethyl trimethoxysilane,
3-glycidoxy-propyltriethoxysilane,
3-isocyanatopropyltriethoxysilane, 3-cyanatopropyltriethoxysilane,
and sodium silicates.
[0014] In certain embodiments, the low density, porous 3-D
structure is associated with the core nanoparticle via
intra-molecular interaction (e.g. covalent bonds, metallic bonds,
and/or ionic bonding) or inter-molecular interaction (e.g. hydrogen
bond, and/or non covalent bonds).
[0015] In certain embodiments, the low density, porous 3-D
structure is a stable crosslinked coating with thickness ranging
from 1 nm to 1000 nm (e.g. from 1 nm to 500 nm). In certain
embodiments, the thickness of the low density, porous 3-D structure
is controllable, so is the number of payloads that could be
carried. As a result, the nanostructures when systematically
applied as injectable agents into the blood stream of a living
subjects can accumulate at a disease region, such as a tumor or
inflammation site. In certain embodiments, the nanostructure is
capable of carrying or being associated with one or more payloads.
In certain embodiments, the payloads to be carried or associated
with the nanostructure include, but are not limited to, a
detectable agent (e.g. a fluorescent molecule, a chemo-luminescent
molecule, a bio-luminescent molecule, a radioisotope, a MRI
contrast agent, a CT contrast agent, an enzyme-substrate label,
and/or a coloring agent), a targeting moiety (e.g. an antibody, an
antigen, a ligand, an aptamer, a peptide, a nucleic acid, a
polynucleotide, a polysaccharide, sugar, fatty acid, steroids,
pyrimidines, and/or a hapten), a binding partner (e.g. antigen,
antibody, receptor, ligand, DNA, RNA, peptide, aptamer, biotin,
avidin, streptavidin, lectin, carbohydrate, Protein A, antibody Fc,
desthiobiotin, and/or iminobiotin), a biological active agent (e.g.
therapeutic agents, proteins, antibodies, peptides, nucleic acids,
enzymes, thermal-responsive molecules, optical-responsive
molecules, electronic-responsive molecules, magnetic-responsive
molecules, pH-responsive molecules, enzymatic responsive molecules
and/or chemical compounds), a drug, a therapeutic agent, a
radiological agent, a chemological agent, a small molecule drug, a
biological drug (e.g., peptides, proteins, antibodies, antigens,
nucleic acids, aptamers and the like) and combinations thereof,
which can be used to image, detect, study, monitor, evaluate,
screen a disease, condition, and/or related biological event. In
certain embodiments, the nanostructure comprises a first payload
and a second payload.
[0016] Another aspect of the present disclosure relates to
compositions comprising a first IDed porous nanostructure and a
first piece of nucleic acid, wherein the nucleic acid is associated
with the IDed porous nanostructure.
[0017] In certain embodiments, the nucleic acid is a primer, a
probe or a fragment of DNA.
[0018] In certain embodiments, the compositions further comprise a
magnetic particle,
[0019] wherein the magnetic particle is associated with one end of
the first nucleic acid and the IDed porous nanostructure is
associated with the opposite end of the first nucleic acid.
[0020] In certain embodiments, the first nanostructure is
magnetic.
[0021] In certain embodiments, the compositions further comprise a
second IDed porous nanostructure and a second nucleic acid, wherein
the second nucleic acid is associated with the second IDed porous
nanostructure and complements to said first nucleic acid, and
wherein the second IDed nanostructure is not the first
nanostructure. In certain embodiments, the second nanostructure is
magnetic.
[0022] Another aspect of the present disclosure relates to a
mixture comprising a first IDed nanostructure and a second IDed
nanostructure, wherein the first IDed nanostructure is associated
with a first nucleic acid and the second IDed nanostructure is
associated with a second nucleic acid. In certain embodiments, the
first and second nanostructures are both magnetic. In certain
embodiments, the mixture further comprises a third IDed
nanostructure, wherein the third IDed nanostructure is associated
with a third nucleic acid and complements with the first or second
nucleic acids. In certain embodiments, the third nanostructure is
magnetic.
[0023] Another aspect of the present disclosure relates to methods
of detecting a condition in a sample or a subject, comprising:
hybridizing a DNA fragment from the sample or the subject with the
composition provided herein, and detecting the presence of double
stranded DNA in the IDed nanostructure which indicates the presence
of a condition in the sample or subject.
[0024] Another aspect of the present disclosure relates to methods
of detecting a condition in a sample or a subject, comprising:
hybridizing a DNA fragment from the sample or the subject with the
composition provided herein in a solution, adding a single-stranded
endonuclease into the solution, subjecting the solution to a
magnetic field, and detecting the presence or coding signal of IDed
nanostructure which indicates the presence of a condition in the
sample or subject.
[0025] Another aspect of the present disclosure relates to methods
of detecting the coding signals of a plurality of IDed
nanostructures in a solution simultaneously, comprising passing a
light from a solution comprising a plurality of IDed nanostructures
through a microlens array to a photosensor array, and processing
the light data to identify each IDed nanostructure in the
solution.
[0026] Another aspect of the present disclosure relates to methods
of detecting the coding signal of a plurality of IDed
nanostructures on a surface, comprising assembling the plurality of
IDed nanostructures from a solution onto the surface. In certain
embodiments, the assembling is based on chemical interaction, or
based on magnetic interaction. In certain embodiments, the IDed
nanostructures of the composition are assembled in an ordered array
format in the presence of an applied magnetic field.
[0027] Another aspect of the present disclosure relates to methods
of detecting interaction of a nucleic acid with a testing agent,
wherein the nucleic acid is associated with a first IDed porous
nanostructure having a first coding signal, and the testing agent
is associated with a second IDed porous nanostructure having a
second coding signal, comprising: contacting the first IDed porous
nanostructure with the second IDed porous nanostructure, and
detecting the interaction of the first coding signal and the second
coding signal. In certain embodiments, the methods further comprise
assembling the first and the second IDed porous nanostructures from
a solution to a surface.
[0028] Another aspect of the present disclosure relates to methods
of forming an amplified DNA sequence, comprising: extending a
primer in the presence of both a template DNA and a mixture of IDed
nanostructures, wherein each IDed nanostructure is associated with
a unique code and a unique combination of two or three consecutive
nucleotides.
DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1. A schematic comparison of porous nanostructure
incorporating a plurality of payloads (dots) with dense
nanostructures (black network, right).
[0030] FIG. 2. An exemplary TEM image of silanized Au nanoparticles
with core size of Au at .about.20 nm and hydrodynamic size
.about.60 nm. No siliceous coating is visible from the TEM.
[0031] FIG. 3. An exemplary TEM image of silanized quantum dots
with nanoparticle core size of .about.6 nm and hydrodynamic size
.about.200 nm. The siliceous coating is not obviously visible from
the TEM.
[0032] FIG. 4. Exemplary TEM images of coated nanoparticles known
in the art, in which the coatings are obviously observable under
TEM.
[0033] FIG. 5. An exemplary TEM image of porous nanostructure, in
which the diameters of the large core nanoparicles are shown.
[0034] FIG. 6. Illustration of the DNA coding for 1 nucleotide each
sequencing step (left) compared with 2 nucleotides each sequencing
step.
[0035] FIG. 7. Illustration to utilize IDed nanostructures to
detect DNA fragments from tissue or biological samples.
[0036] FIG. 8. Illustration to utilize magnetic IDed nanostructure
to detect DNA fragments from tissue or biological samples.
[0037] FIG. 9. An image of IDed nanostructures under fluorescent
microscope. The IDed nanostructures were incorporated with
different fluorescent molecules, showing red, green and yellow
colors.
[0038] FIG. 10. Illustration to utilize IDed nanostructures to
detect hybridization of DNA strands. For IDed nanostructures, the
ID and the DNA strands on the particle could be paired up. The ID
signal directly corresponds to a specific DNA sequence. For
example, if red and green IDed nanostructures bind together through
the DNA hybridization, the known sequence of the DNA on red
particle could be used to derive/detect DNA sequence on green
particles.
[0039] FIG. 11. DNA hybridization results using IDed
nanostructures. (a) Image of control experiment: mixture of red and
green IDed nanostructures without DNA oligomers. (b)-(m) DNA
hybridization results: red and green IDed nanostructures were
conjugated respectively with complementary DNA oligomeric strands,
and successful hybridization was manifested by the association of
red and green IDed nano structures.
[0040] FIG. 12. IDed fluorescent magnetic nanostructures could be
spread onto a magnetic grid for identification of DNA hybridization
based detection. The IDed fluorescent magnetic nanoparticles were
utilized to identify DNA hybridization by examining the
nanostructures formed in solution through DNA hybridization
connected IDed fluorescent magnetic nanoparticles. These structures
are formed in solution, and dispersed onto a 2D surface using a
magnetic grid. By flowing the solutions through the magnetic grid,
IDed fluorescent magnetic nanoparticles or nanostructures were
captured and spread onto the surface for identification. (a)
Control experiment: mixture of red and green IDed magnetic
nanostructures without DNA oligomers, and accordingly, negligible
red and green particle binding together (yellow color) were
observed. (b) DNA hybridization results: red and green IDed
magnetic nanostructures were conjugated respectively with
complementary DNA oligomeric strands, and the nanostructures are
more packed together onto the magnetic grid, and yellow color were
manifested.
[0041] FIG. 13. Illustration to utilize IDed magnetic
nanostructures to detect hybridization of a first DNA strand and a
second DNA strand with a third DNA strand, in which the first DNA
strand hybridizes to the first portion of the third DNA strand, and
the second DNA strand hybridizes to the second portion of the third
DNA strand.
DETAILED DESCRIPTION OF THE INVENTION
[0042] Before the present disclosure is described in greater
detail, it is to be understood that this disclosure is not limited
to particular embodiments described, and as such may, of course,
vary. It is also to be understood that the terminology used herein
is for the purpose of describing particular embodiments only, and
is not intended to be limiting, since the scope of the present
disclosure will be limited only by the appended claims.
[0043] Where a range of values is provided, it is understood that
each intervening value, to the tenth of the unit of the lower limit
unless the context clearly dictates otherwise, between the upper
and lower limit of that range and any other stated or intervening
value in that stated range, is encompassed within the disclosure.
The upper and lower limits of these smaller ranges may
independently be included in the smaller ranges and are also
encompassed within the disclosure, subject to any specifically
excluded limit in the stated range. Where the stated range includes
one or both of the limits, ranges excluding either or both of those
included limits are also included in the disclosure.
[0044] Unless defined otherwise, all technical and scientific terms
used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which this disclosure belongs.
Although any methods and materials similar or equivalent to those
described herein can also be used in the practice or testing of the
present disclosure, the preferred methods and materials are now
described.
[0045] All publications and patents cited in this specification are
herein incorporated by reference as if each individual publication
or patent were specifically and individually indicated to be
incorporated by reference and are incorporated herein by reference
to disclose and describe the methods and/or materials in connection
with which the publications are cited. The citation of any
publication is for its disclosure prior to the filing date and
should not be construed as an admission that the present disclosure
is not entitled to antedate such publication by virtue of prior
disclosure. Further, the dates of publication provided could be
different from the actual publication dates that may need to be
independently confirmed.
[0046] As will be apparent to those of skill in the art upon
reading this disclosure, each of the individual embodiments
described and illustrated herein has discrete components and
features which may be readily separated from or combined with the
features of any of the other several embodiments without departing
from the scope or spirit of the present disclosure. Any recited
method can be carried out in the order of events recited or in any
other order that is logically possible.
[0047] Embodiments of the present disclosure will employ, unless
otherwise indicated, techniques of chemistry, solid state
chemistry, inorganic chemistry, organic chemistry, physical
chemistry, analytical chemistry, materials chemistry, biochemistry,
biology, molecular biology, recombinant DNA techniques,
pharmacology, imaging, and the like, which are within the skill of
the art. Such techniques are explained fully in the literature.
[0048] Before the embodiments of the present disclosure are
described in detail, it is to be understood that, unless otherwise
indicated, the present disclosure is not limited to particular
materials, reagents, reaction materials, manufacturing processes,
or the like, as such can vary. It is also to be understood that the
terminology used herein is for purposes of describing particular
embodiments only, and is not intended to be limiting. It is also
possible in the present disclosure that steps can be executed in
different sequence where this is logically possible.
[0049] The following embodiments are put forth so as to provide
those of ordinary skill in the art with a complete disclosure and
description of how to perform the methods and use the probes
disclosed and claimed herein. Efforts have been made to ensure
accuracy with respect to numbers (e.g., amounts, temperature,
etc.), but some errors and deviations should be accounted for.
[0050] It must be noted that, as used in the specification and the
appended claims, the singular forms "a," "an," and "the" include
plural referents unless the context clearly dictates otherwise.
Thus, for example, reference to "a compound" includes a plurality
of compounds. In this specification and in the claims that follow,
reference will be made to a number of terms that shall be defined
to have the following meanings unless a contrary intention is
apparent.
[0051] Porous Nanostructures
[0052] One aspect of the present disclosure relates to porous
nanostructures comprising at least one core nanoparticle embedded
in or coated with a low density, porous 3-D structure.
[0053] The core nanoparticle used herein includes, but not limited
to, a superparamagnetic iron oxide (SPIO) nanoparticle, and a
non-SPIO nanoparticle.
[0054] The SPIO nanoparticle is an iron oxide nanoparticle, either
maghemite (.gamma.-Fe.sub.2O.sub.3) or magnetite (Fe.sub.3O.sub.4),
or nanoparticles composed of both phases. The SPIO can be
synthesized with a suitable method and dispersed as a colloidal
solution in organic solvents or water. Methods to synthesize the
SPIO nanoparticles are known in the art (see, for example, Morteza
Mahmoudi et al, Superparamagnetic Iron Oxide Nanoparticles:
Synthesis, Surface Engineering, Cytotoxicity and Biomedical
Applications, published by Nova Science Pub Inc, 2011). In one
embodiment, the SPIO nanoparticles can be made through wet chemical
synthesis methods which involve co-precipitation of Fe.sup.2+ and
Fe.sup.3+ salts in the presence of an alkaline medium. During the
synthesis, nitrogen may be introduced to control oxidation,
surfactants and suitable polymers may be added to inhibit
agglomeration or control particle size, and/or emulsions (such as
water-in-oil microemulsions) may be used to modulate the physical
properties of the SPIO nanoparticle (see, for example, Jonathan W.
Gunn, The preparation and characterization of superparamagnetic
nanoparticles for biomedical imaging and therapeutic application,
published by ProQuest, 2008). In another embodiment, the SPIO
nanoparticles can be generated by thermal decomposition of iron
pentacarbonyl, alone or in combination with transition metal
carbonyls, optionally in the presence of one or more surfactants
(e.g. lauric acid and oleic acid) and/or oxidatants (e.g.
trimethylamine-N-oxide), and in a suitable solvent (e.g. dioctyl
ether or hexadecane) (see, for example, US patent application
20060093555). In another embodiment, the SPIO nanoparticles can
also be made through gas deposition methods, which involves laser
vaporization of iron in a helium atmosphere containing different
concentrations of oxygen (see, Miller J. S. et al., Magnetism:
Nanosized magnetic materials, published by Wiley-VCH, 2002).
[0055] In certain embodiments, the SPIO nanoparticles are those
disclosed in US patent application US20100008862.
[0056] The non-SPIO nanoparticles include, for example, metallic
nanoparticles (e.g., gold or silver nanoparticles (see, e.g.,
Hiroki Hiramatsu, F. E. O., Chemistry of Materials 16, 2509-2511
(2004)), semiconductor nanoparticles (e.g., quantum dots with
individual or multiple components such as CdSe/ZnS (see, e.g., M.
Bruchez, et al., science 281, 2013-2016 (1998))), doped heavy metal
free quantum dots (see, e.g., Narayan Pradhan et al, J. Am. chem.
Soc. 129, 3339-3347 (2007)) or other semiconductor quantum dots);
polymeric nanoparticles (e.g., particles made of one or a
combination of PLGA (poly(lactic-co-glycolic acid) (see, e.g.,
Minsoung Rhee et al., Adv. Mater. 23, H79-H83 (2011)), PCL
(polycaprolactone) (see, e.g., Marianne Labet et al., Chem. Soc.
Rev. 38, 3484-3504 (2009)), PEG (poly ethylene glycol) or other
polymers); siliceous nanoparticles; and non-SPIO magnetic
nanoparticles (e.g., MnFe.sub.2O.sub.4 (see, e.g., Jae-Hyun Lee et
al., Nature Medicine 13, 95-99 (2006)), synthetic antiferromagnetic
nanoparticles (SAF) (see, e.g., A. Fu et al., Angew. Chem. Int. Ed.
48, 1620-1624 (2009)), and other types of magnetic
nanoparticles).
[0057] The non-SPIO nanoparticles can be prepared or synthesized
using suitable methods known in the art, such as for example,
sol-gel synthesis method, water-in-oil micro-emulsion method, gas
deposition method and so on. For example, gold nanoparticles can be
made by reduction of chloroaurate solutions (e.g. HAuCl.sub.4) by a
reducing agent such as citrate, or acetone dicarboxylate. For
another example, CdS semiconductor nanoparticle can be prepared
from Cd(ClO.sub.4).sub.2 and Na.sub.2S on the surface of silica
particles. For another example, II-VI semiconductor nanoparticles
can be synthesized based on pyrolysis of organometallic reagents
such as dimethyl cadmium and trioctylphosphine selenide, after
injection into a hot coordinating solvent (see, e.g. Gunter Schmid,
Nanoparticles: From Theory to Application, published by John Wiley
& Sons, 2011). Doped heavy metal free quantum dots, for example
Mn-doped ZnSe quantum dots can be prepared using nucleation-doping
strategy, in which small-sized MnSe nanoclusters are formed as the
core and ZnSe layers are overcoated on the core under high
temperatures. For another example, polymeric nanoparticles can be
prepared by emulsifying a polymer in a two-phase solvent system,
inducing nanosized polymer droplets by sonication or
homogenization, and evaporating the organic solvent to obtain the
nanoparticles. For another example, siliceous nanoparticles can be
prepared by sol-gel synthesis, in which silicon alkoxide precursors
(e.g. TMOS or TEOS) are hydrolyzed in a mixture of water and
ethanol in the presence of an acid or a base catalyst, the
hydrolyzed monomers are condensed with vigorous stirring and the
resulting silica nanoparticles can be collected. For another
example, SAFs, a non-SPIO magnetic nanoparticle, can be prepared by
depositing a ferromagenetic layer on each of the two sides of a
nonmagnetic space layer (e.g. ruthenium metal), along with a
chemical etchable copper release layer and protective tantalum
surface layers, using ion-bean deposition in a high vacuum, and the
SAF nanoparticle can be released after removing the protective
layer and selective etching of copper.
[0058] The size of the core nanoparticles ranges from 1 nm to 100
nm in size (preferable 1-50 nm, 2-40 nm, 5-20 nm, 1 nm, 2 nm, 3 nm,
4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14
nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm in size). The size of
nanoparticles can be controlled by selecting appropriate synthesis
methods and/or systems. For example, to control the size of
nanoparticles, synthesis of nanoparticles can be carried out in a
polar solvent which provides ionic species that can adsorb on the
surface of the nanoparticles, thereby providing electrostatic
effect and particle-particle repulsive force to help stabilize the
nanoparticles and inhibit the growth of the nanoparticles. For
another example, nanoparticles can be synthesized in a
micro-heterogeneous system that allows compartmentalization of
nanoparticles in constrained cavities or domains. Such a
micro-heterogeneous system may include, liquid crystals, mono and
multilayers, direct micelles, reversed micelles, microemulsions and
vesicles. To obtain nanoparticles within a desired size range, the
synthesis conditions may be properly controlled or varied to
provide for, e.g., a desired solution concentration or a desired
cavity range (a detailed review can be found at, e.g. Vincenzo
Liveri, Controlled synthesis of nanoparticles in microheterogeneous
systems, Published by Springer, 2006).
[0059] The shape of the core nanoparticles can be spherical, cubic,
rod shaped (see, e.g., A. Fu et al., Nano Letters, 7, 179-182
(2007)), tetrapo-shaped (see, e.g., L. Manna et al., Nature
Materials, 2, 382-385 (2003)), pyramidal, multi-armed, nanotube,
nanowire, nanofiber, nanoplate, or any other suitable shapes.
Methods are known in the art to control the shape of the
nanoparticles during the preparation (see, e.g. Waseda Y. et al.,
Morphology control of materials and nanoparticles: advanced
materials processing and characterization, published by Springer,
2004). For example, when the nanoparticles are prepared by the
bottom-up process (i.e. from molecule to nanoparticle), a shape
controller which adsorbs strongly to a specific crystal plane may
be added to control the growth rate of the particle.
[0060] A single core nanoparticle may comprise a single
nanoparticle or a plurality or a cluster of mini-nanoparticles (A.
Fu et al., J. Am. chem. Soc. 126, 10832-10833 (2004), J. Ge et al.,
Angew. Chem. Int. Ed. 46, 4342-4345 (2007), Zhenda Lu et al., Nano
Letters 11, 3404-3412 (2011).). The mini-nanoparticles can be
homogeneous (e.g., made of the same composition/materials or having
same size) or heterogeneous (e.g., made of different
compositions/materials or having different sizes). A cluster of
homogeneous mini-nanoparticles refers to a pool of particles having
substantially the same features or characteristics or consisting of
substantially the same materials. A cluster of heterogeneous
mini-nanoparticles refers to a pool of particles having different
features or characteristics or consisting of substantially
different materials. For example, a heterogeneous mini-nanoparticle
may comprise a quantum dot in the center and a discrete number of
gold (Au) nanocrystals attached to the quantum dot. Different
nanoparticles in a heterogeneous nanoparticle pool do not need to
associate with each other at first, but rather, they could be
individually and separately associated with the low density porous
structure.
[0061] In certain embodiments, a nanostructure disclosed comprising
a plurality of core nanoparticles embedded in or coated with a low
density, porous 3-D structure. For example, the nanostructure
contains 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,
18, 19, 20, 25, 30, 35, 40, 50, 60, 70, 80, 90, 100, 100s or 1000s
core nanoparticles.
[0062] In certain embodiments, the low density, porous 3-D
structure refers to a structure with density much lower (e.g. 10s
times, 20s times, 30s times, 50s times, 70s times, 100s times) than
existing mesoporous nanoparticles (e.g. mesoporous nanoparticles
having a pore size ranging from 2 nm to 50 nm). (A. Vincent, et.
al., J. Phys. Chem. C, 2007, 111, 8291-8298. J. E. Lee, et. al., J.
Am. Chem. Soc., 2010, 132, 552-557. Y.-S. Lin, et. al., J. Am.
Chem. Soc., 2011, 133, 20444-20457. Z. Lu, Angew. Chem. Int. Ed.,
2010, 49, 1862-1866.)
[0063] In certain embodiments, the low density, porous 3-D
structure refers to a structure having a density of <1.0 g/cc
(e.g., <100 mg/cc, <10 mg/cc, <5 mg/cc, <1 mg/cc,
<0.5 mg/cc, <0.4 mg/cc, <0.3 mg/cc, <0.2 mg/cc, or
<0.1 mg/cc) (for example, from 0.01 mg/cc to 10 mg/cc, from 0.01
mg/cc to 8 mg/cc, from 0.01 mg/cc to 5 mg/cc, from 0.01 mg/cc to 3
mg/cc, from 0.01 mg/cc to 1 mg/cc, from 0.01 mg/cc to 1 mg/cc, from
0.01 mg/cc to 0.8 mg/cc, from 0.01 mg/cc to 0.5 mg/cc, from 0.01
mg/cc to 0.3 mg/cc, from 0.01 mg/cc to 1000 mg/cc, from 0.01 mg/cc
to 915 mg/cc, from 0.01 mg/cc to 900 mg/cc, from 0.01 mg/cc to 800
mg/cc, from 0.01 mg/cc to 700 mg/cc, from 0.01 mg/cc to 600 mg/cc,
from 0.01 mg/cc to 500 mg/cc, from 0.1 mg/cc to 800 mg/cc, from 0.1
mg/cc to 700 mg/cc, from 0.1 mg/cc to 1000 mg/cc, from 1 mg/cc to
1000 mg/cc, from 5 mg/cc to 1000 mg/cc, from 10 mg/cc to 1000
mg/cc, from 20 mg/cc to 1000 mg/cc, from 30 mg/cc to 1000 mg/cc,
from 30 mg/cc to 1000 mg/cc, from 30 mg/cc to 900 mg/cc, from 30
mg/cc to 800 mg/cc, or from 30 mg/cc to 700 mg/cc).
[0064] The density of 3-D structure can be determined using various
methods known in the art (see, e.g., Lowell, S. et al.,
Characterization of porous solids and powders: surface area, pore
size and density, published by Springer, 2004). Exemplary methods
include, Brunauer Emmett Teller (BET) method and helium pycnometry
(see, e.g., Varadan V. K. et al., Nanoscience and Nanotechnology in
Engineering, published by World Scientific, 2010). Briefly, in BET
method, dry powders of the testing 3-D structure is placed in a
testing chamber to which helium and nitrogen gas are fed, and the
change in temperature is recorded and the results are analyzed and
extrapolated to calculate the density of the testing sample. In
helium pycnometry method, dry powders of the testing 3-D structure
are filled with helium, and the helium pressure produced by a
variation of volume is studied to provide for the density. The
measured density based on the dry power samples does not reflect
the real density of the 3-D structure because of the ultralow
density of the 3-D structure, the framework easily collapses during
the drying process, hence providing much smaller numbers in the
porosity measurement than when the 3-D structure is fully extended,
for example, like when the 3-D structure is fully extended in a
buffer solution.
[0065] In certain embodiments, the density of the 3-D structure can
be determined using the dry mass of the 3-D structure divided by
the total volume of such 3-D structure in an aqueous solution. For
example, dry mass of the core particles with and without the 3-D
structure can be determined respectively, and the difference
between the two would be the total mass of the 3-D structure.
Similarly, the volume of a core particle with and without the 3-D
structure in an aqueous solution can be determined respectively,
and the difference between the two would be the volume of the 3-D
structure on the core particle in an aqueous solution.
[0066] In certain embodiments, the porous nanostructure can be
dispersed as multiple large nanoparticles coated with the 3-D
structure in an aqueous solution, in such case, the total volume of
the 3-D structure can be calculated as the average volume of the
3-D structure for an individual large nanoparticle multiplied with
the number of the large nanoparticles.
[0067] For each individual large nanoparticle, the size (e.g.
radius) of the particle with 3-D structure can be determined with
Dynamic Light Scattering (DLS) techniques, and the size (e.g.
radius) of the particle core without the 3-D structure can be
determined under Transmission Electron Microscope (TEM), as the 3-D
structure is substantially invisible under TEM. Accordingly, the
volume of the 3-D structure on an individual large nanoparticle can
be obtained by subtracting the volume of the particle without 3-D
structure from the volume of the particle with the 3-D
structure.
[0068] The number of large nanoparticles for a given core mass can
be calculated using any suitable methods. For example, an
individual large nanoparticle may be composed of a plurality of
small nanoparticles which are visible under TEM. In such case, the
average size and volume of a small nanoparticle can be determined
based on measurements under TEM, and the average mass of a small
nanoparticle can be determined by multiplying the known density of
the core material with the volume of the small particle. By
dividing the core mass with the average mass of a small
nanoparticle, the total number of small nanoparticles can be
estimated. For an individual large nanoparticle, the average number
of small nanoparticles in it can be determined under TEM.
Accordingly, the number of large nanoparticles for a given core
mass can be estimated by dividing the total number of small
nanoparticles with the average number of small nanoparticels in an
individual large nanoparticle.
[0069] Alternatively, the low density, porous 3-D structure refers
to a structure having 40%-99.9% (preferably 50% to 99.9%) of empty
space or pores in the structure, where 80% of the pores having size
of 1 nm to 500 nm in pore radius.
[0070] The porosity of the 3-D structure can be characterized by
the Gas/Vapor adsorption method. In this technique, usually
nitrogen, at its boiling point, is adsorbed on the solid sample.
The amount of gas adsorbed at a particular partial pressure could
be used to calculate the specific surface area of the material
through the Brunauer, Emmit and Teller (BET) nitrogen
adsorption/desorption equation. The pore sizes are calculated by
the Kelvin equation or the modified Kelvin equation, the BJH
equation (see, e.g. D. Niu et al., J. Am. chem. Soc. 132,
15144-15147 (2010)).
[0071] The porosity of the 3-D structure can also be characterized
by mercury porosimetry (see, e.g. Varadan V. K. et al., supra).
Briefly, gas is evacuated from the 3-D structure, and then the
structure is immersed in mercury. As mercury is non-wetting at room
temperature, an external pressure is applied to gradually force
mercury into the sample. By monitoring the incremental volume of
mercury intruded for each applied pressure, the pore size can be
calculated based on the Washburn equation.
[0072] Alternatively, the low density, porous 3-D structure refers
to a structure that has a material property, that is, the porous
structure (except to the core nanoparticle or core nanoparticles)
could not be obviously observed or substantially transparent under
transmission electron microscope, for example, even when the
feature size of the 3-D structure is in the 10s or 100s nanometer
range. The term "obviously observed" or "substantially transparent"
as used herein means that, the thickness of the 3-D structure can
be readily estimated or determined based on the image of the 3-D
structure under TEM. The nanostructure (e.g. nanoparticles coated
with or embedded in/on a low density porous 3-D structure) can be
observed or measured by ways known in the art. For example, the
size (e.g. radius) of the nanostructure with the 3-D structure can
be measured using DLS methods, and the size (e.g. radius) of the
core particle without the 3-D structure can be measured under TEM.
In certain embodiments, the thickness of the 3-D structure is
measured as 10s, 100s nanometer range by DLS, but cannot be readily
determined under TEM. For example, when the nanostructures provided
herein are observed under Transmission Electron Microscope (TEM),
the nanoparticles can be identified, however, the low density
porous 3-D structure can not be obviously observed, or is almost
transparent (e.g., see FIGS. 2 and 3). This distinguishes the
nanostructures provided herein from those reported in the art (see,
FIG. 4) that comprise nanoparticles coated with crosslinked and
size tunable 3-D structure, including the mesoporous silica
nanoparticles or coating (see, e.g., J. Kim, et. al., J. Am. Chem.
Soc., 2006, 128, 688-689; J. Kim, et. al., Angew. Chem. Int. Ed.,
2008, 47, 8438-8441). This feature also indicates that the low
density porous 3-D structure provided herein has a much lower
density and/or is highly porous in comparison to other coated
nanoparticles known in the art.
[0073] The porosity of the 3-D structure can be further evaluated
by the capacity to load different molecules (see, e.g. Wang L. et
al., Nano Research 1, 99-115 (2008)). As the 3-D structure provided
herein has a low density, it is envisaged that more payload can be
associated with the 3-D structure than with other coated
nanoparticles (see, e.g. FIG. 1). For example, when 3-D structure
is loaded with organic fluorophores such as Rhodamin, over 10.sup.5
Rhodamin molecules can be loaded to 3-D structure of one
nanoparticle.
[0074] In certain embodiments, the low density structure refers to
a structure capable of absorbing or carrying a fluorescent payload
whose fluorescence intensity is at least 100 fold of that of the
free fluorescent molecule (e.g. at least 150 fold, 200 fold, 250
fold, 300 fold, 350 fold, 400 fold, 450 fold, 500 fold, 550 fold or
600 fold). The fluorescence intensity of a loaded nanoparticle can
be quantified under the same excitation and emission wave lengths
as that of the fluorescent molecules. The fluorescence intensity of
the loaded low density structure indicates the payload of the
fluorescent molecule, and also indirectly reflects the porosity of
the low density structure.
[0075] In certain embodiments, the low density, porous 3-D
structure is made of silane-containing or silane-like molecules
(e.g., silanes, organosilanes, alkoxysilanes, silicates and
derivatives thereof).
[0076] In certain embodiments, the silane-containing molecule
comprises an organosilane, which is also known as silane coupling
agent. Organosilane has a general formula of R.sub.xSiY.sub.(4-x),
wherein R group is an alkyl, aryl or organofunctional group. Y
group is a methoxy, ethoxy or acetoxy group. x is 1, 2 or 3. The R
group could render a specific function such as to associate the
organosilane molecule with the surface of the core nanoparticle or
other payloads through covalent or non-covalent interactions. The Y
group is hydrolysable and capable of forming a siloxane bond to
crosslink with another organosilane molecule. Exemplary R groups
include, without limitation, disulphidealkyl, aminoalkyl,
mercaptoalkyl, vinylalkyl, epoxyalkyl, and methacrylalkyl,
carboxylalkyl groups. The alkyl group in an R group can be
methylene, ethylene, propylene, and etc. Exemplary Y groups
include, without limitation, alkoxyl such as OCH.sub.3,
OC.sub.2H.sub.5, and OC.sub.2H.sub.4OCH.sub.3. For example, the
organosilane can be amino-propyl-trimethoxysilane,
mercapto-propyl-trimethoxysilane, carboxyl-propyl-trimethoxysilane,
amino-propyl-triethoxysilane, mercapto-propyl-triethoxysilane,
carboxyl-propyl-triethoxysilane, Bis[3-(triethoxysilyl)
propyl]-tetrasulfide, Bis[3-(triethoxysilyl) propyl]-disulfide,
aminopropyltriethoxysilane, N-2-(aminoethyl)-3-amino
propyltrimethoxysilane, Vinyltrimethoxysilane,
Vinyl-tris(2-methoxyethoxy) silane, 3-methacryloxypropyltrimethoxy
silane, 2-(3,4-epoxycyclohexy)-ethyl trimethoxysilane,
3-glycidoxy-propyltriethoxysilane,
3-isocyanatopropyltriethoxysilane, and
3-cyanatopropyltriethoxysilane.
[0077] The 3-D structure interacts with the core nanoparticles
through 1) intra-molecular interaction such as covalent bonds
(e.g., Sigma bond, Pi bond, Delta bond, Double bond, Triple bond,
Quadruple bond, Quintuple bond, Sextuple bond, 3c-2e,3c-4-e,4c-2e,
Agostic bond, Bent bond, Dipolar bond, Pi backbond, Conjugation,
Hyperconjugation, Aromaticity, Hapticity, and Antibonding),
metallic bonds (e.g., chelating interactions with the metal atom in
the core nanoparticle), or ionic bonding (cation .pi.-bond and salt
bond), and 2) inter-molecular interaction such as hydrogen bond
(e.g., Dihydrogen bond, Dihydrogen complex, Low-barrier hydrogen
bond, Symmetric hydrogen bond) and non covalent bonds (e.g.,
hydrophobic, hydrophilic, charge-charge, or 7r-stacking
interactions, van der Waals force, London dispersion force,
Mechanical bond, Halogen bond, Aurophilicity, Intercalation,
Stacking, Entropic force, and chemical polarity).
[0078] Methods for Preparing the Porous Nanostructure
[0079] Another aspect of the present disclosure relates to methods
of forming a nanostructure comprising at least one core
nanoparticle with low-density, porous 3-D structure. For example,
the nanostructure is formed by coating or surrounding one or more
core nanoparticle with low density, porous 3-D structure such that
the particle(s) is or are embedded in the 3-D structure.
[0080] The low-density, porous 3-D structure is formed by the
depositing, or covering of the surface of the core nanoparticle
through the assembly or cross-linking of silane-containing or
silane-like molecules. The low density porous 3-D structure can be
prepared by a silanization process on the surface of the core
nanoparticles. Silanization process includes, for example, the
steps of crosslinking silicon-containing or silane-like molecules
(e.g., alkoxysilanes such as amino-propyl-trimethoxysilane,
mercapto-propyl-trimethoxysilane, or sodium silicate) under acidic
or basic conditions.
[0081] In certain embodiments, an acidic or a basic catalyst is
used in the crosslinking. Exemplary acid catalyst include, without
limitation, a protonic acid catalyst (e.g. nitric acid, acetic acid
and sulphonic acids) and Lewis acid catalyst (e.g. boron
trifluoride, boron trifluoride monoethylamine complex, boron
trifluoride methanol complex, FeCl.sub.3, AlCl.sub.3, ZnCl.sub.2,
and ZnBr.sub.2). Exemplary basic catalysts include, an amine or a
quaternary ammonium compound such as tetramethyl ammonium hydroxide
and ammonia hydroxide.
[0082] The silanization process may include one or more stages, for
example, a priming stage in which the 3-D structure starts to form,
a growth stage in which a layer of siliceous structure is readily
formed on the core nanoparticle and more are to be formed, and/or
an ending stage in which the 3-D structure is about to be completed
(e.g. the outer surface of the 3-D structure is about to be
formed). During the silanization process, one or more
silane-containing molecules can be added at different stages of the
process. For example, in the priming stage, organosilanes such as
aminopropyl trimethoxyl silane or mercaptopropyl trimethoxyl silane
can be added to initiate the silanization on the core nanoparticle
surface. For another example, silane molecules having fewer alkoxy
group (e.g. only 2 alkoxy group) can be added to the reaction at
the growth stage of silanization. For another example, at the
ending stage of silanization, organo silane molecules with one or a
variety of different functional groups may be added. These
functional groups can be amino, carboxyl, mercapto, or phosphonate
group, which can be further conjugated with other molecules, e.g.
hydrophilic agent, a biologically active agent, a detectable label,
an optical responsive group, electronic responsive group, magnetic
responsive group, enzymatic responsive group or pH responsive
group, or a binding partner, so as to allow further modification of
the 3-D structure in terms of stability, solubility, biological
compatibility, capability of being further conjugation or
derivation, or affinity to payload. Alternatively, the functional
groups can also be a group readily conjugated with other molecules
(e.g. a group conjugated with biologically active agent, a thermal
responsive molecule, an optical responsive molecule, an electronic
responsive molecule, a magnetic responsive molecule, a pH
responsive molecule, an enzymatic responsive molecule, a detectable
label, or a binding partner such as biotin or avidin).
[0083] To control the formation of low density siliceous structure,
the preparation further includes density reducing procedures such
as introducing air bubbles in the reaction or formation, increasing
reaction temperature, microwaving, sonicating, vertexing,
labquakering, and/or adjusting the chemical composition of the
reaction to adjust the degree of the crosslinking of the silane
molecules. Without being bound to theory, it is believed that these
procedures can help make the reaction medium homogeneous, well
dispersed and promote the formation of low density porous 3-D
structure with increased voids or porosity.
[0084] In certain embodiments, the density reducing procedure
comprises sonicating the reaction or formation mixture. The
conditions of the sonicating procedure (e.g. duration) in the
silanization process can be properly selected to produce a desired
porosity in the resulting low density porous 3-D structure. For
example, the sonicating can be applied throughout a certain stage
of the silanization process. The duration of sonicating in a
silanization stage may last for, e.g. at least 1 hour, 1.5 hours, 2
hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours. In certain
embodiments, sonicating is applied in each stage of the
silanization process.
[0085] In certain embodiments, the density reducing procedures
comprise introducing at least one alcohol to the reaction. In
certain embodiments, the alcohol has at least 3 (e.g. at least 4,
at least 5 or at least 6) carbon atoms. For example, the alcohol
may have 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 or more carbon atoms. In
certain embodiments, the alcohol can be monohydric alcohols, or
polyhydric alcohols. Illustrative examples of monohydric alcohols
include, propanol, butanol, pentanol, hexyl alcohol, etc.
Illustrative examples of polyhydric alcohols include, propylene
glycol, glycerol, threitol, xylitol, etc. In certain embodiments,
the alcohol can have a saturated carbon chain or an unsaturated
carbon chain. An alcohol having a saturated carbon chain can be
represented as C.sub.nH.sub.(2n+2)O in chemical formula. In certain
embodiments, n is no less than 3, or no less than 4, or no less
than 5 (e.g. n=3, 4, 5, 6, 7, 8, 9, 10, 11, 12 or more). Alcohol
with an unsaturated carbon chain has a double or a triple bond
between two carbon atoms. In certain embodiments, the alcohol can
be a cyclic alcohol, for example, cyclohexanol, inositol, or
menthol.
[0086] In certain embodiments, the alcohol can have a straight
carbon chain (e.g. n-propyl alcohol, n-butyl alcohol, n-pentyl
alcohol, n-hexyl alcohol, etc) or a branched carbon chain (e.g.
isopropyl alcohol, isobutyl alcohol, tert-butyl alcohol, etc). In
certain embodiments, the alcohol is present in a volume fraction of
about 30% to about 70% (e.g. about 30% to about 70%, about 30% to
about 60%, about 30% to about 55%, about 40% to about 70%, about
45% to about 70%, about 40% to about 60%). In certain embodiments,
the alcohol is present in volume fraction of around 50% (e.g.
around 45%, around 46%, around 47%, around 48%, around 49%, around
50%, around 51%, around 52%, around 53%, around 54%, around 55%,
around 56%, around 57%, around 58%, around 59%, or around
60%,).
[0087] In certain embodiments, the density reducing procedure
comprises introducing air bubbles to the reaction. In certain
embodiments, the air bubbles can be in constant presence during the
reaction process. The air bubbles can be introduced to the reaction
through any suitable methods, for example, by blowing bubbles to
the reaction, or by introducing a gas-producing agent to the
reaction mixture.
[0088] Other experimental conditions can also be optimized to
provide for formation of a desired low density porous 3-D
structure. Such experimental conditions include, for example, the
concentration of the core nanoparticles, the concentration of the
catalyst, the ratio of the concentration of the catalyst and the
core nanoparticle, the temperature at which the low density
siliceous structure is formed, or the molecular structure of the
organosilanes.
[0089] In certain embodiments, the method further comprises
introducing one or more functional groups within in or on the
surface of the porous structure. The functional groups may be
introduced during the formation of the porous structure during the
cross-linking process, for example, by adding silicon-containing
compounds containing such functional groups during the
cross-linking, in particular, during the ending stage of the
cross-linking process. The functional groups may also be introduced
after the formation of the cross-linking product, for example, by
introducing functional groups to the surface of the cross-linking
product by chemical modification. In certain embodiments, the
functional groups are inherent in the porous structure.
[0090] The functional groups serve as linkage between the porous
structure and payloads. Examples of the functional groups include,
but are not limited to amino, mercapto, carboxyl, phosphonate,
biotin, streptavidin, avidin, hydroxyl, alkyl or other hydrophobic
molecules, polyethylene glycol or other hydrophilic molecules, and
photo cleavable, thermo cleavable or pH responsive linkers.
[0091] In certain embodiments, the method further comprises
purifying the obtained nanostructure product. The purification may
include use of dialysis, tangential flow filtration, diafiltration,
or combinations thereof.
[0092] The thickness of the low density porous 3-D structure, which
directly correlates to the size of the nanostructure, could be
controlled (e.g. from 1 nm to 1000 nm) by, for example, modifying
the quantity of the silane-containing molecules (e.g.
trialkoxysilane or sodium silicate), the reaction time, and time
lapse between reaction steps and such kind of reaction
parameters.
[0093] The thickness of the 3-D structure can be about 1 to 5 nm
thick. In certain embodiments, the thickness can be about 1 to 10
nm thick. In certain embodiments, the thickness can be about 1 to
20 nm thick. In certain embodiments, the thickness can be about 1
to 30 nm thick. In certain embodiments, the thickness can be about
1 to 40 nm thick. In certain embodiments, the thickness can be
about 1 to 50 nm thick. In certain embodiments, the thickness can
be about 1 to 60 nm thick. In certain embodiments, the thickness
can be about 1 to 100 nm thick. In certain embodiments, the
thickness can be about 1 to 500 nm thick. In certain embodiments,
the thickness can be about 1 to 1000 nm thick.
[0094] After the low-density, porous 3-D structure is formed on the
surface of the core nanoparticle, the core nanoparticle is embedded
in the 3-D structure. The resulting nanostructure can have a
thickness (e.g., the longest dimension of the nanostructure or a
diameter if the structure is a sphere) of about 1 to 1000 nm, 1 to
100 nm, or 1 to 10 nm. In another embodiment, the nanostructure can
have a diameter of about 1 to 30 nm. In another embodiment, the
nanostructure can have a diameter of about 500 nm. In another
embodiment, the nanostructure can have a diameter of about 100 nm.
In another embodiment, the nanostructure can have a diameter of
about 50 nm. In another embodiment, the nanostructure can have a
diameter of about 30 nm. In another embodiment, the nanostructure
can have a diameter of about 10 nm.
[0095] Payloads
[0096] In certain embodiments, the nanostructures provided herein
carry or are associated with a payload. The payloads to be carried
or associated with the nanostructure include, but are not limited
to, a detectable agent, a targeting moiety, a binding partner, a
biological active agent, a drug, a therapeutic agent, a
radiological agent, a chemological agent, a small molecule drug, a
biological drug (e.g., peptides, proteins, antibodies, antigens,
nucleic acids, aptamers, and the like) and combinations thereof,
which can be used to image, detect, study, monitor, evaluate,
screen, and/or a disease, condition, or related biological event.
Payloads may be physically absorbed into the porous structure or
linked to the porous structure through functional groups disclosed
herein.
[0097] A detectable agent can be a fluorescent molecule, a
chemo-luminescent molecule, a bio-luminescent molecule, a
radioisotope, a MRI contrast agent, a CT contrast agent, an
enzyme-substrate label, and/or a coloring agent etc. Examples of
fluorescent molecules include, without limitation, fluorescent
compounds (fluorophores) which can include, but are not limited to:
1,5 IAEDANS; 1,8-ANS; 4-Methylumbelliferone;
5-carboxy-2,7-dichlorofluorescein; 5-Carboxyfluorescein (5-FAM);
5-Carboxynapthofluorescein; 5-Carboxytetramethylrhodamine
(5-TAMRA); 5-FAM (5-Carboxyfluorescein); 5-HAT (Hydroxy
Tryptamine); 5-Hydroxy Tryptamine (HAT); 5-ROX
(carboxy-X-rhodamine); 5-TAMRA (5-Carboxytetramethylrhodamine);
6-Carboxyrhodamine 6G; 6-CR 6G; 6-JOE; 7-Amino-4-methylcoumarin;
7-Aminoactinomycin D (7-AAD); 7-Hydroxy-4-methylcoumarin;
9-Amino-6-chloro-2-methoxyacridine; ABQ; Acid Fuchsin; ACMA
(9-Amino-6-chloro-2-methoxyacridine); Acridine Orange; Acridine
Red; Acridine Yellow; Acriflavin; Acriflavin Feulgen SITSA;
Aequorin (Photoprotein); AFPs--AutoFluorescent Protein--(Quantum
Biotechnologies); Alexa.RTM. Fluor 350; Alexa.RTM. Fluor 405;
Alexa.RTM. Fluor 500; Alexa Fluor 430.TM.; Alexa Fluor 488.TM.;
Alexa Fluor 532.TM.; Alexa Fluor 546.TM.; Alexa Fluor 568.TM.;
Alexa Fluor 594.TM.; Alexa Fluor 633.TM.; Alexa Fluor 647.TM.;
Alexa Fluor 660.TM.; Alexa Fluor 680.TM.; Alizarin Complexon;
Alizarin Red; Allophycocyanin (APC); AMC, AMCA-S; AMCA
(Aminomethylcoumarin); AMCA-X; Aminoactinomycin D; Aminocoumarin;
Aminomethylcoumarin (AMCA); Anilin Blue; Anthrocyl stearate; APC
(Allophycocyanin); APC-Cy7; APTRA-BTC; APTS; Astrazon Brilliant Red
4G; Astrazon Orange R; Astrazon Red 6B; Astrazon Yellow 7 GLL;
Atabrine; ATTO-TAG.TM. CBQCA; ATTO-TAG.TM. FQ; Auramine;
Aurophosphine G; Aurophosphine; BAO 9 (Bisaminophenyloxadiazole);
BCECF (high pH); BCECF (low pH); Berberine Sulphate; Beta
Lactamase; Bimane; Bisbenzamide; Bisbenzimide (Hoechst); bis-BTC;
Blancophor FFG; Blancophor SV; BOBO.TM.-1; BOBO.TM.-3; Bodipy
492/515; Bodipy 493/503; Bodipy 500/510; Bodipy 505/515; Bodipy
530/550; Bodipy 542/563; Bodipy 558/568; Bodipy 564/570; Bodipy
576/589; Bodipy 581/591; Bodipy 630/650-X; Bodipy 650/665-X; Bodipy
665/676; Bodipy Fl; Bodipy FL ATP; Bodipy Fl-Ceramide; Bodipy R6G
SE; Bodipy TMR; Bodipy TMR-X conjugate; Bodipy TMR-X, SE; Bodipy
TR; Bodipy TR ATP; Bodipy TR-X SE; BO-PRO.TM.-1; BO-PRO.TM.-3;
Brilliant Sulphoflavin FF; BTC; BTC-5N; Calcein; Calcein Blue;
Calcium Crimson.TM.; Calcium Green; Calcium Green-1 Ca.sup.2+ Dye;
Calcium Green-2 Ca.sup.2+; Calcium Green-5N Ca.sup.2+; Calcium
Green-C18 Ca.sup.2+; Calcium Orange; Calcofluor White;
Carboxy-X-rhodamine (5-ROX); Cascade Blue.TM.; Cascade Yellow;
Catecholamine; CCF.sub.2 (GeneBlazer); CFDA; Chlorophyll;
Chromomycin A; Chromomycin A; CL-NERF; CMFDA; Coumarin Phalloidin;
C-phycocyanine; CPM Methylcoumarin; CTC; CTC Formazan;
Cy.sub.2.TM.; Cy3.18; Cy3.5.TM.; Cy3.TM.; Cy5.18; Cy5.5.TM.;
Cy5.TM.; Cy7.TM.; cyclic AMP Fluorosensor (FiCRhR); Dabcyl; Dansyl;
Dansyl Amine; Dansyl Cadaverine; Dansyl Chloride; Dansyl DHPE;
Dansyl fluoride; DAPI; Dapoxyl; Dapoxyl 2; Dapoxyl 3' DCFDA; DCFH
(Dichlorodihydrofluorescein Diacetate); DDAO; DHR (Dihydrorhodamine
123); Di-4-ANEPPS; Di-8-ANEPPS (non-ratio); DiA (4-Di-16-ASP);
Dichlorodihydrofluorescein Diacetate (DCFH); DiD-Lipophilic Tracer;
DiD (DiIC18(5)); DID S; Dihydrorhodamine 123 (DHR); DiI
(DiIC18(3)); Dinitrophenol; DiO (DiOC18(3)); DiR; DiR (DiIC18(7));
DM-NERF (high pH); DNP; Dopamine; DTAF; DY-630-NHS; DY-635-NHS; ELF
97; Eosin; Erythrosin; Erythrosin ITC; Ethidium Bromide; Ethidium
homodimer-1 (EthD-1); Euchrysin; EukoLight; Europium (III)
chloride; EYFP; Fast Blue; FDA; Feulgen (Pararosaniline); FIF
(Formaldehyd Induced Fluorescence); FITC; Flazo Orange; Fluo-3;
Fluo-4; Fluorescein (FITC); Fluorescein Diacetate; Fluoro-Emerald;
Fluoro-Gold (Hydroxystilbamidine); Fluor-Ruby; Fluor X; FM
1-43.TM.; FM 4-46; Fura Red.TM. (high pH); Fura Red.TM./Fluo-3;
Fura-2; Fura-2/BCECF; Genacryl Brilliant Red B; Genacryl Brilliant
Yellow 10GF; Genacryl Pink 3G; Genacryl Yellow SGF; GeneBlazer
(CCF.sub.2); Gloxalic Acid; Granular blue; Haematoporphyrin;
Hoechst 33258; Hoechst 33342; Hoechst 34580; HPTS; Hydroxycoumarin;
Hydroxystilbamidine (FluoroGold); Hydroxytryptamine; Indo-1, high
calcium; Indo-1, low calcium; Indodicarbocyanine (DiD);
Indotricarbocyanine (DiR); Intrawhite Cf; JC-1; JO-JO-1; JO-PRO-1;
LaserPro; Laurodan; LDS 751 (DNA); LDS 751 (RNA); Leucophor PAF;
Leucophor SF; Leucophor WS; Lissamine Rhodamine; Lissamine
Rhodamine B; Calcein/Ethidium homodimer; LOLO-1; LO-PRO-1; Lucifer
Yellow; Lyso Tracker Blue; Lyso Tracker Blue-White; Lyso Tracker
Green; Lyso Tracker Red; Lyso Tracker Yellow; LysoSensor Blue;
LysoSensor Green; LysoSensor Yellow/Blue; Mag Green; Magdala Red
(Phloxin B); Mag-Fura Red; Mag-Fura-2; Mag-Fura-5; Mag-Indo-1;
Magnesium Green; Magnesium Orange; Malachite Green; Marina Blue;
Maxilon Brilliant Flavin 10 GFF; Maxilon Brilliant Flavin 8 GFF;
Merocyanin; Methoxycoumarin; Mitotracker Green FM; Mitotracker
Orange; Mitotracker Red; Mitramycin; Monobromobimane;
Monobromobimane (mBBr-GSH); Monochlorobimane; MPS (Methyl Green
Pyronine Stilbene); NBD; NBD Amine; Nile Red; Nitrobenzoxadidole;
Noradrenaline; Nuclear Fast Red; Nuclear Yellow; Nylosan Brilliant
lavin E8G; Oregon Green; Oregon Green 488-X; Oregon Green.TM.;
Oregon Green.TM. 488; Oregon Green.TM. 500; Oregon Green.TM. 514;
Pacific Blue; Pararosaniline (Feulgen); PBFI; PE-Cy5; PE-Cy7;
PerCP; PerCP-Cy5.5; PE-TexasRed [Red 613]; Phloxin B (Magdala Red);
Phorwite AR; Phorwite BKL; Phorwite Rev; Phorwite RPA; Phosphine
3R; PhotoResist; Phycoerythrin B [PE]; Phycoerythrin R [PE]; PKH26
(Sigma); PKH67; PMIA; Pontochrome Blue Black; POPO-1; POPO-3;
PO-PRO-1; PO-PRO-3; Primuline; Procion Yellow; Propidium lodid
(PI); PYMPO; Pyrene; Pyronine; Pyronine B; Pyrozal Brilliant Flavin
7GF; QSY 7; Quinacrine Mustard; Red 613 [PE-TexasRed]; Resorufin;
RH 414; Rhod-2; Rhodamine; Rhodamine 110; Rhodamine 123; Rhodamine
5 GLD; Rhodamine 6G; Rhodamine B; Rhodamine B 200; Rhodamine B
extra; Rhodamine BB; Rhodamine BG; Rhodamine Green; Rhodamine
Phallicidine; Rhodamine Phalloidine; Rhodamine Red; Rhodamine WT;
Rose Bengal; R-phycocyanine; R-phycoerythrin (PE); S65A; S65C;
S65L; S65T; SBFI; Serotonin; Sevron Brilliant Red 2B; Sevron
Brilliant Red 4G; Sevron Brilliant Red B; Sevron Orange; Sevron
Yellow L; SITS; SITS (Primuline); SITS (Stilbene Isothiosulphonic
Acid); SNAFL calcein; SNAFL-1; SNAFL-2; SNARF calcein; SNARF1;
Sodium Green; SpectrumAqua; SpectrumGreen; SpectrumOrange; Spectrum
Red; SPQ (6-methoxy-N-(3-sulfopropyl)quinolinium); Stilbene;
Sulphorhodamine B can C; Sulphorhodamine Extra; SYTO 11; SYTO 12;
SYTO 13; SYTO 14; SYTO 15; SYTO 16; SYTO 17; SYTO 18; SYTO 20; SYTO
21; SYTO 22; SYTO 23; SYTO 24; SYTO 25; SYTO 40; SYTO 41; SYTO 42;
SYTO 43; SYTO 44; SYTO 45; SYTO 59; SYTO 60; SYTO 61; SYTO 62; SYTO
63; SYTO 64; SYTO 80; SYTO 81; SYTO 82; SYTO 83; SYTO 84; SYTO 85;
SYTOX Blue; SYTOX Green; SYTOX Orange; Tetracycline;
Tetramethylrhodamine (TRITC); Texas Red.TM.; Texas Red-X.TM.
conjugate; Thiadicarbocyanine (DiSC3); Thiazine Red R; Thiazole
Orange; Thioflavin 5; Thioflavin S; Thioflavin TCN; Thiolyte;
Thiozole Orange; Tinopol CBS (Calcofluor White); TMR; TO-PRO-1;
TO-PRO-3; TO-PRO-5; TOTO-1; TOTO-3; TriColor (PE-Cy5); TRITC
TetramethylRodaminelsoThioCyanate; True Blue; TruRed; Ultralite;
Uranine B; Uvitex SFC; WW 781; X-Rhodamine; XRITC; Xylene Orange;
Y66F; Y66H; Y66W; YO-PRO-1; YO-PRO-3; YOYO-1; YOYO-3, Sybr Green,
Thiazole orange (interchelating dyes), fluorescent semiconductor
nanoparticles, lanthanides or combinations thereof.
[0098] Examples of radioisotopes include, .sup.123I, .sup.124I,
.sup.125I, .sup.131I, .sup.35S, .sup.3H, .sup.111In, .sup.112In,
.sup.14C, .sup.64Cu, .sup.67Cu, .sup.86Y, .sup.88Y, .sup.90Y,
.sup.177Lu, .sup.211At, .sup.186Re, .sup.188Re, .sup.153Sm,
.sup.212Bi, .sup.32P, .sup.18F, .sup.201Tl, .sup.67Ga, .sup.137Cs
and other radioisotopes.
[0099] Examples of enzyme-substrate labels include, luciferases
(e.g., firefly luciferase and bacterial luciferase), luciferin,
2,3-dihydrophthalazinedionesm, alate dehydrogenase, urease,
peroxidase such as horseradish peroxidase (HRPO), alkaline
phosphatase, -galactosidase, glucoamylase, lysozyme, saccharide
oxidases (e.g., glucose oxidase, galactose oxidase, and
glucose-6-phosphate dehydrogenase), heterocyclic oxidases (such as
uricase and xanthine oxidase), lactoperoxidase, microperoxidase,
and the like.
[0100] A targeting moiety has affinity to an interested target
(e.g., a cell, a cellular component, a tissue, a protein, an
antibody, an antigen, a DNA, a RNA and the like). Examples of a
targeting moiety include, antibodies (e.g. antibodies to tumor
surface antigens, antibodies to cell-specific antigens, or
antibodies to receptors), a ligand to a receptor (e.g. growth
factors, hormones, cytokines, or neurotransmitters), aptamers,
peptides, antigens, nucleic acids, polynucleotides,
polysaccharides, sugars, fatty acids, steroids, purines,
pyrimidines, a hapten or combinations thereof.
[0101] Examples of a binding partner include, antibodies, antigens,
receptors, ligands, DNA, RNA, peptide, aptamer, biotin, avidin,
strepavidin, lectin, carbohydrate, Protein A, antibody Fc,
desthiobiotin, and iminobiotin.
[0102] Examples of a biologically active agent include, therapeutic
agents, proteins, antibodies, peptides, nucleic acids, enzymes,
thermal-responsive molecules, optical-responsive molecules,
electronic-responsive molecules, magnetic-responsive molecules,
pH-responsive molecules, enzymatic responsive molecules and/or
chemical compounds. Exemplary of therapeutic agents include,
without limitation, local anesthetics, antiepileptic drugs and
anticonvulsants, anti-alzheimer's disease drugs, analgesics,
antipodaghc, anti-hypertensive drugs, antiarrhythmic drugs,
diuretic drugs, drugs for treating liver diseases, drugs for
treating pancreatic diseases, antihistamine drugs, anti-allergic
drugs, glucocorticoid drugs, sex hormone drugs and contraceptive
drugs, hypoglycemic drugs, anti-osteoporosis drugs, antibiotics,
sulfonamides, quinolones, and other synthetic antibacterial drugs,
antituberculous drugs, antiviral drugs, anti-neoplasm drugs, and
immunomodulators.
[0103] With respect to antigens or antibodies thereof, a protein of
interest can be any one or more of the following antigens including
but not limited to: 1) leukocyte markers, such as CD2, CD3, CD4,
CD5, CD6, CD7, CD8, CD11a,b,c, CD13, CD14, CD18, CD19, CD20, CD22,
CD23, CD27 and its ligand, CD28 and its ligands B7.1, B7.2, B7.3,
CD29 and its ligand, CD30 and its ligand, CD40 and its ligand gp39,
CD44, CD45 and isoforms, CDw52 (Campath antigen), CD56, CD58, CD69,
CD72, CTLA-4, LFA-1 and TCR; 2) histocompatibility antigens, such
as MHC class I or II, the Lewis Y antigens, SLex, SLey, SLea, and
SLeb; 3) integrins, such as VLA-1, VLA-2, VLA-3, VLA-4, VLA-5,
VLA-6, and LFA-1; 4) adhesion molecules, such as Mac-1 and p150,
95; 5) selectins, such as L-selectin, P-selectin, and E-selectin
and their counterreceptors VCAM-1, ICAM-1, ICAM-2, and LFA-3; 6)
interleukins, such as IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7,
IL-8, IL-10, IL-11, IL-12, IL-13, IL-14; and IL-15; 7) interleukin
receptors, such as IL-1R, IL-2R, IL-4R, IL-5R, IL-6R, IL-7R, IL-8R,
IL-10R, IL-11R, IL-12R, IL-13R, IL-14R, and IL-15R; 8) chemokines,
such as PF4, RANTES, MIPl.alpha., MCPJ, NAP-2, Grou, Grog, and
IL-8; 9) growth factors, such as TNFalpha, TGFbeta, TSH, VEGF/VPF,
PTHrP, EGF family, FGF, PDGF family, endothelin, and gastrin
releasing peptide (GRP); 10) growth factor receptors, such as
TNFalphaR, RGFbetaR, TSHR, VEGFR/VPFR, FGFR, EGFR, PTHrPR, PDGFR
family, EPO-R, GCSF-R and other hematopoietic receptors; 11)
interferon receptors, such as IFN.alpha.R, IFN.beta.R, and
IFN.gamma.R; 12) Igs and their receptors, such as IgE, FceRI, and
FCeR11; 13) tumor antigens, such as her2-neu, mucin, CEA and
endosialin; 14) allergens, such as house dust mite antigen, lol pl
(grass) antigens, and urushiol; 15) viral proteins, such as CMV
glycoproteins B, H, and gCIII, HIV-1 envelope glycoproteins, RSV
envelope glycoproteins, HSV envelope glycoproteins, EBV envelope
glycoproteins, VZV envelope glycoproteins, HPV envelope
glycoproteins, Hepatitis family surface antigens; 16) toxins, such
as pseudomonas endotoxin and osteopontin/uropontin, snake venom,
and bee venom; 17) blood factors, such as complement C3b,
complement C5a, complement C5b-9, Rh factor, fibrinogen, fibrin,
and myelin associated growth inhibitor; 18) enzymes, such as
cholesterol ester transfer protein, membrane bound matrix
metalloproteases, and glutamic acid decarboxylase (GAD); and 19)
miscellaneous antigens including ganglioside GD3, ganglioside GM2,
LMP1, LMP2, eosinophil major basic protein, eosinophil cationic
protein, PANCA, Amadori protein, Type IV collagen, glycated lipids,
.gamma.-interferon, A7, P-glycoprotein and Fas (AFO-1) and
oxidized-LDL.
[0104] In certain embodiments, a protein of interest can be
antibodies or fragments thereof which bind to an antigen
(non-limiting example of antigens are shown as above). The
antibodies or fragments can be polyclonal, monoclonal, of animal
origin (e.g., murine, rabbit, camel), of human origin (e.g., fully
human), chimeric, humanized, variable regions, CDRs, ScFv,
bispecific, diabody, or other forms of antibodies with
antigen-binding capabilities.
[0105] The payload may be introduced during or after the formation
of the nanostructures. For example, when the nanostructure is
formed through silanization process, the payload (e.g. a
fluorescent compound) can be introduced to the silanization system,
so as to allow the incorporation of the payload into the
nanostructure during the silanization process. For another example,
the payload may be mixed with the readily formed nanostructure,
e.g. in solution, dispersion, suspension, emulsion etc, to allow
incorporation of the payload to the porous compartment of the
nanostructure, or to allow conjugation of the payload to the
functional groups on the nanostructure.
[0106] In certain embodiment, at least one payload can be
associated with the porous structure. For example, only one group
of homogenous payloads are associated with the porous structure.
For another example, the first payload and the second payload are
associated with the porous structure. While both payloads are
selected from the groups consisting of a detectable agent, a
targeting moiety, a binding partner, a biological active agent, a
drug, a therapeutic agent, a radiological agent, a chemological
agent, a small molecule drug, a biological drug (e.g., peptides,
proteins, antibodies, antigens, nucleic acids, aptamers, and the
like); the first payload is not the same as the second payload. For
instance, the first payload is a targeting agent that lead the
nanostructure to specifically binds to or be associated with a
target (e.g., a cancer cell), and the second payload is a
detectable gent (for diagnosis) or a therapeutic agent (for
treatment).
[0107] In certain embodiments, the first payload is associated with
the porous structure in one area of the structure and the second
payload is associated with the porous structure in another area of
the structure so that the nanostructure can be directional or
oriented with respect to the distribution of payloads in the
nanostructure. Such site selective modification could be achieved
by depositing the porous structure on a substrate, then partially
coating the substrate with a protective polymer layer, such as
poly(3-hexyl-thiophene) (P3HT) and poly(methyl methacrylate) that
could be dissolved using certain solvents such as chloroform or
pyridine after the site selective modification is finished. (Liu
H., et. al., nano letters, 2004, vol 4., 2397-2401). A second
modification could be achieved after the protective layer is
removed and the unmodified nanostructure is exposed and further
modified with different payloads. Further, the nanostructure could
be deposited on the substrate with bonding through cleavable
molecules, for example, photo cleavable molecules such as
photocleavable biotin amine reactive labeling reagents
(www.ambergen.com), then the nanostructure could be released after
site selective modifications. In addition, with cleavable linker
molecule bound to the substrate, the nanostructures could be
released after the first site selective modification (SSM1). SSM1
could include both functional groups for linking the SSM1 modified
area to a substrate in the next site selective modification step
and payloads for signal generating, drugs or other functional
purposes. The procedure could be repeated for SSM2. By controlling
the protective polymer layer thickness, 3rd, 4th or more site
selective modification steps could be carried out to render the
nanostructures multiple regions of different payloads.
[0108] Products by Process
[0109] Another aspect of the present disclosure relates to
nanostructures prepared by any of the methods provided herein. The
nanostructures prepared herein may be optionally isolated,
purified, dried, or associated with one or more payloads, using
methods described herein and/or conventional methods known in the
art. The nanostructures prepared in the present disclosure can be
further characterized for the 3-D structure, such as density,
porosity, surface areas, thickness etc. of the 3-D structure.
Optionally, the payloads may be characterized as well, such as the
amount of the payload or the detectable signal of the payload.
[0110] IDed Nanostructures
[0111] Another aspect of the present disclosure relates to
compositions comprising a porous nanostructure of a known
characteristics and a fragment of nucleic acid having a known
sequence. In certain embodiments, the porous nanostructures have
been disclosed in U.S. Prov. Appl. 61/589, 777 (all references
cited in the present disclosure are incorporated herein in their
entirety). In certain embodiments, the porous nanostructure has the
characteristics as disclosed herein.
[0112] In certain embodiments, the present disclosure provides a
composition comprising a first IDed porous nanostructure and a
first piece of nucleic acid, wherein the nucleic acid is associated
with the IDed porous nanostructure. The term "IDed" as used herein,
means that the porous nanostructure is associated with a known code
or a known label that allows identification of the porous
nanostructure. "Code" as used herein, refers to a molecule capable
of generating a detectable signal that distinguishes one IDed
porous nanostructure from another.
[0113] The characteristics or the identity of a given nanostructure
can be based on multiplexed optical coding system as disclosed in
Han et al., Nature Biotechnology, Vol. 19, pp: 631-635 (2001) or
U.S. patent application Ser. No. 10/185, 226. Briefly, multicolor
semiconductor quantum-dots (QDs) are embedded in the porous
nanostructure. For each QD, there is a given intensity (within the
levels of, for example. 0-10) and a given color (wavelength). For
each single color coding, the porous nanostructure has different
intensity of QDs depending on the number of QDs embedded therein.
If QDs of multiple colors (n colors) and multiple intensity (m
levels of intensity) are used, then the porous nanostructures may
have a total number of unique identities or codes, which is equal
to m to the exponent of m less one (e-1). In addition, since the
porous structure can be associated with additional payloads (e.g.,
fluorescent organic molecules), if there are Y number of additional
fluorescent colors available, the total number of code can be
Y.times.(m.sup.n-1).
[0114] Alternatively or additionally, the identity of a given IDed
porous nanostructure can be based on the fluorescent payload
associated therewith. Fluorescent payloads of different colors can
be embedded in the porous nanostructures, thereby generating
different IDed porous nanostructures coded by different fluorescent
colors or signals (see, for example, FIG. 9).
[0115] In certain embodiments, the IDed porous nanostructure has
magnetic property. Magnetic property can facilitate manipulation
(e.g. separation or delivery) of the nanostructures using magnetic
interaction. Magnetic IDed porous nanostructures can comprise one
or a cluster of SIPO nanoparticles as core nanoparticles. The
magnetic IDed nanostructures can be attracted to or magnetically
guided to a target site when subject to a strong magnetic field,
for example a magnetic field from high-filed and/or high-gradient
magnets. For example, a magnet (e.g. magnetic grid) can be placed
in the proximity of the nanostructures so as to attract the
magnetic nano structures.
[0116] In certain embodiments, an IDed porous nanostructure is
associated with at least one piece of nucleic acid. The fragment of
a nucleic acid can be associated with the IDed porous nanostructure
in non-covalent interactions (e.g. hydrogen bonds, ionic bonds,
etc) or covalent interactions. In certain embodiments, the nucleic
acid is associated to one or more functional groups on the IDed
porous nanostructure. Any functional groups as disclosed herein can
be used (e.g. amino, carboxyl, mercapto, phosphonate group, biotin,
streptavidin, avidin, hydroxyl, alkyl or other molecules, linkers
or groups). In certain embodiments, the nucleic acid is associated
with the IDed porous nanostructure through streptavidin-biotin
interactions. For example, the IDed porous nanostructure has
streptavidin on its surface, and the nucleic acid is conjugated
with biotin. After combining the two, streptavidin strongly binds
to avidin and thereby associating the IDed porous nanostructure
with the fragment of the nucleic acid. In certain embodiments, the
present disclosure further provides an IDed porous nanostructure
capable of be associated with a nucleic acid, through one or more
functional groups (e.g. streptavidin, biotin, amino, carboxyl,
mercapto, phosphonate group, etc.) on the IDed porous
nanostructure. The piece of the nucleic acid can be in a suitable
length, for example, at least 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 25, 30, 40, 50, 60, 70, 80, 90, 100 or more
bases.
[0117] In certain embodiments, the IDed porous nanostructure is
associated with a fragment of a nucleic acid with a known sequence.
The nucleic acid can be a primer or a sequence probe or a fragment
for detection.
[0118] In certain embodiments, the IDed porous nanostructure
associated with a nucleic acid has magnetic property.
[0119] In certain embodiments, the compositions further comprise a
second IDed porous nanostructure and a second nucleic acid, wherein
the second nucleic acid is associated with the second IDed porous
nanostructure and complements to said first nucleic acid, and
wherein the second IDed nanostructure is not the first
nanostructure. The first and the second IDed porous nanostructure
can have different coding signals, so that they can be
distinguished from each other when separated. The first and the
second nucleic acids can hybridize to each other and thereby
allowing association between the first and the second IDed porous
nanostructures.
[0120] In certain embodiments, the first nucleic acid may be a
probe of known sequence and the second nucleic acid may be a sample
nucleic acid. If the sample nucleic acid binds to the probe, then
the first and the second IDed nanostructures can be associated as
manifested by the co-localization of the coding signals of the
first and the second nanostructures. Accordingly, association of
the first and the second IDed nanostructure indicates that the
sample nucleic acid hybridizes to the probe sequence or comprises a
complement of the probe sequence.
[0121] Either of the first and the second IDed porous
nanostructures can be magnetic. A magnetic field can be applied to
allow separation of the associated products of the first and the
second IDed nanostructures. The separated products can be further
observed for both coding signals, and presence of both signals in
co-localization indicates association.
[0122] Another aspect of the present disclosure relates to a
mixture comprising a first IDed nanostructure and a second IDed
nanostructure, wherein the first IDed nanostructure is associated
with a first nucleic acid and the second IDed nanostructure is
associated with a second nucleic acid. In certain embodiments, the
first and second nanostructures are both magnetic. In certain
embodiments, the mixture further comprises a third IDed
nanostructure, wherein the third IDed nanostructure is associated
with a third nucleic acid and complements with the first or second
nucleic acids. In certain embodiments, the third nanostructure is
magnetic.
[0123] A plurality of probes of known sequences can be each
associated with a different IDed nanostructure, such that one ID
corresponds to one probe. A sample nucleic acid can be associated
with a further IDed nanostructure, and then be mixed with the
plurality of probes on the IDed nanostructures. If the sample
nucleic acid hybridizes with any of the probes, the corresponding
coding signals of the IDed nanostructures can be detected in
association with each other. In this way, the sample nucleic acid
can be screened against different probes in one reaction. In
certain embodiments, any or all of the IDed nanostructures can be
magnetic. For example, the IDed nanostructure associated with the
sample nucleic acid can be magnetic. After the hybridization
reaction, the sample nucleic acid can be separated through magnetic
interaction, and coding signals can be detected to identify the
probe(s) that hybridize with the sample nucleic acid.
[0124] In certain embodiments, the capture probes or polynucleotide
concatemers disclosed in U.S. Pat. No. 7,910,354 can be deposited
or linked or associated to the IDed porous nanostructures and used
to form amplified DNA clusters.
[0125] In certain embodiments, the probe can be associated or
linked with the IDed nanostructure. In conventional technologies, a
set of four fluorescent colors are used to represent the change of
a single nucleotide (See FIG. 6, Current Technology, F--fluoresce).
In the present disclosure, since the nanostructures can be
associated with a total number of Y (m.sup.n-1) codes, probes
having exponentiation of four can be made and used in, for example,
sequencing. As shown in FIG. 6, for two consecutive nucleotides to
be detected, sixteen (4.times.4) IDed nanostructures can be
associated with each probe and each can be detected based on their
coding (N--IDed nanostructure). By the same token, three
consecutive nucleotides can be detected by using 64 different
coded, IDed nanostructures. For Z number of consecutive nucleotides
to be detected, e different IDed nanostructures can be used, as far
as 4.sup.Z<Y.times.(m.sup.n-1). In certain embodiment, a known
fragment of nucleotide is associated or linked with an IDed
nanostructure. As shown in FIG. 7, a fragment of DNA with mutation
is associated with the IDed nanostructures and contacted with DNA
fragments from a subject or a sample (e.g., cells or tissues or
organs). The hybridized solution can further be treated with single
stranded DNA endonucleases (e.g., S1 endonuclease). The mixture
solution is further treated with a double stranded DNA dye. The
detection of the presence of double stranded DNA on a known IDed
nanostructure indicates the presence of DNAs in the subject or
sample, and therefore, a condition associated with the DNA (e.g.,
SNPs or a disease condition). In detection of the presence of
double stranded DNA the sample can be assayed in a temperature that
denature double stranded DNA and in a second temperature that
stabilized double stranded DNA, the different emission indicates
the presence of double stranded DNA in the IDed nanostructure.
[0126] In certain embodiments, the IDed porous nanostructure
associated with a piece of nucleic acid further comprises a
magnetic particle, and the magnetic particle is associated with one
end of the nucleic acid and the IDed porous nanostructure is
associated with the other end of the nucleic acid. The magnetic
particle can facilitate manipulation of the nucleic acid, and the
IDed porous nanostructure can provide for detection or
identification of the nucleic acid. Such a differently conjugated
nucleic acid can be prepared using suitable methods. In certain
embodiments, each end of the nucleic acid can have a different
functional group which allows selective conjugation of the IDed
porous nanostructure or the magnetic particle. In certain
embodiments, one end of the nucleic acid is protected when the
other end is being conjugated, and then deprotected for a further
conjugation. As shown in FIG. 8, a probe fragment (single strand)
is linked to an IDed nanostructure and a magnetic particle (e.g.,
magnetic nanostructure) on both ends and is hybridized with
fragments from a subject or a sample. The hybridization mixture is
then subject to endonuclease specific to single stranded DNA. If
the probe fragment is hybridized to a fragment from the sample, the
complex is intact in the presence of the nuclease. If no
hybridization occurs, the probe fragment is cleaved and the IDed
nanostructure is separated from the magnetic particle. The mixture
is then subject to a magnetic field. The IDed nanostructures are
detected (if there is hybridization) and the coding signal(s)
indicates the presence of a target DNA which corresponds to a
condition in the subject or the sample. If there is no
hybridization, then only the magnetic particles associated with no
IDed nanostructure are pulled down and no coding can be
detected.
[0127] In certain embodiments, a plurality of primers or probes can
be associated with a single IDed nanostructure. For example, an
IDed nanostructure carries a pair of primers and is subject to
polymerase chain reaction (PCR). The presence of amplicon (e.g.,
via double stranded DNA dye) can be detected and quantified. If
multiple IDed nanostructures (each has a pair of primer) are used
in a PCR mixture, then a multiplex real-time PCR can be performed,
the presence and the quantification of each amplicon can be
detected.
[0128] The term "double stranded DNA dye" used herein refers to a
fluorescent dye that (1) is related to a fragment of DNA and (2)
emits at a different wavelength in the presence of double stranded
form from the presence of single stranded form. The dye increases
its emission in the presence of double stranded DNA and decreases
its emission when duplex DNA unwinds. Examples include, but are not
limited to, ethidium bromide, YO-PRO-1, Hoechst 33258, SYBR Gold,
and SYBR Green I. A double stranded DNA intercalating dye is not
covalently linked to a primer or a nucleic acid template. Ethidium
bromide is a fluorescent chemical that intercalates between base
pairs in a double stranded DNA fragment and is commonly used to
detect DNA following gel electrophoresis. When excited by
ultraviolet light between 254 nm and 366 nm, it emits fluorescent
light at 590 nm. The DNA-ethidium bromide complex produces about 50
times more fluorescence than ethidium bromide in the presence of
single stranded DNA. SYBR Green I is excited at 497 nm and emits at
520 nm. The fluorescence intensity of SYBR Green I increases over
100 fold upon binding to double stranded DNA against single
stranded DNA. An alternative to SYBR Green I is SYBR Gold
introduced by Molecular Probes Inc. Similar to SYBR Green I, the
fluorescence emission of SYBR Gold enhances in the presence of DNA
in duplex and decreases when double stranded DNA unwinds. However,
SYBR Gold's excitation peak is at 495 nm and the emission peak is
at 537 nm. SYBR Gold reportedly appears more stable than SYBR Green
I. Hoechst 33258 is a known bisbenzimide double stranded DNA dye
that binds to the AT rich regions of DNA in duplex. Hoechst 33258
excites at 350 nm and emits at 450 nm. YO-PRO-1, exciting at 450 nm
and emitting at 550 nm, has been reported to be a double stranded
DNA specific dye. In a preferred embodiment of the present
invention, the double stranded DNA dye is SYBR Green I.
[0129] In certain embodiments, a probe can be associated with a
first IDed nanostructure, and a sample nucleic acid can be
associated with a second nanostructure. As shown in FIG. 10, the
first and the second IDed nanostructures are different in codes,
e.g. one is red and the other is green. The first probe-IDed
nanostructure and the second sample-IDed nanostructure are mixed to
allow hybridization. If the probe and the sample nucleic acid
hybridize with each other, then the association or co-localization
of the first and the second IDed nanostructures can be
detected.
[0130] In certain embodiments, a first probe can be associated with
a first IDed nanostructure, and a second probe can be associated
with a second IDed nanostructure, where the first probe and the
second probe are capable of hybridizing to a respective portion of
a sample nucleic acid (e.g. the first probe hybridizes to the first
half of the sample, and the second probe hybridizes to the second
half of the sample). As shown in FIG. 13, the first and the second
IDed nanostructures are different in coding signals, e.g. one is
red and the other is green. If the sample nucleic acid is present,
then both the first and the second probes would be associated with
the sample nucleic acid, thereby resulting in detection of
association or co-localization of the first and the second IDed
nanostructures.
[0131] In certain embodiments, the present disclosure further
provides a mixture comprising a first IDed nanostructure and a
second IDed nanostructure, wherein the first IDed nanostructure has
a first coding signal and the second IDed nanostructure has a
second coding signal. In certain embodimens, the first IDed
nanostructure has magnetic property while the second IDed
nanostructure has not.
[0132] Methods of Detection and/or Use
[0133] In certain embodiments, a single or a plurality of IDed
nanostructures as disclosed herein can be used and detected at the
same time, preferably in mixture or solution. The IDed
nanostructure associated with nucleic acid, primers, probes, or
fragments can be detected.
[0134] Another aspect of the present disclosure relates to methods
of detecting the coding signals of a plurality of IDed
nanostructures in a solution simultaneously, comprising passing a
light from a solution comprising a plurality of IDed nanostructures
through a microlens array to a photosensor array, and processing
the light data to identify each IDed nanostructure in the solution.
The methods can be used to detect the coding signals (the intensity
and color) of a nanostructure or a plurality of nanostructure in
solution (without the needs for array or substrate) at the same
time or in real time. For example, as disclosed in U.S. Pat. No.
7,936,392, light sources passing through the solution containing a
plurality of IDed nanostructure and the value of passing through
light is detected by photosensors. Light data is then collected
through an imaging arrangement and processed to facilitate focusing
and optical correction via software. As a result, the information
about the IDed nanostructures (e.g., the color and intensity) are
recoded by passing the light through once without the need for
focusing image on each focal plane. The same image computation is
also used in microscope. Under the microscopic setting, the
solution is imaged by passing light from a microlens array to a
photosensor array to simultaneously detect light from the solution
which is passed through different directions to different
locations. The light data is then analyzed to gain datasets for all
IDed nanostructures in the solution in the single shot (For
detailed information, see U.S. Pat. No. 7,723,662).
[0135] Another aspect of the present invention relates to a method
of detecting the coding signals of a plurality of IDed
nanostructures on a surface by assembling the IDed nanostructures
from the solution onto the surface. The assemble can be based on
chemical interaction, for example, forming of a covalent binding
between the IDed nanostructure and the corresponding functional
groups on the surface, or biological interaction, for example,
biotin-streptavidin interaction, by making functional arrays of
appropriate biomolecules on the surface. The assemble can also be
based on magnetic interaction. For example the IDed nanostructures
can be associated with a magnetic particle which can be attracted
in response to an applied magnetic field. The IDed nanostructure
could also be assembled onto a surface in an ordered array format
using the interactions between the magnetic content of the IDed
nanostructure and a magnetizable or magnetic grid. The assembling
of the IDed nanostructures from solution to a surface can greatly
improve or facilitate the detection and/or quantification of the
IDed nanostructures. For example, assemble of the IDed
nanostructures on a surface allows imaging and observation of the
IDed nanostructures on one field under a microscope, in contrast,
IDed nanostructures scattered in a solution can be difficult to
image or quantify under a microscope.
[0136] Another aspect of the present invention related to the
detection of coding signals of IDed nanostructures. Although it is
not necessary to place the IDed nanostructures onto substrate
(e.g., solution based detection as disclosed herein), the IDed
nanostructures can be placed onto a substrate, in the same fashion
DNA nanoballs or other conventional nanoparticles can be placed
onto a substrate and detection occurs after the IDed nanostructures
are on the substrate. In certain embodiments, the IDed
nanostructures can be distributed onto a magnetic substrate (e.g.,
a magnetic grid).
[0137] Another aspect of the present disclosure relates to methods
of forming an amplified DNA sequence, comprising extending a primer
in the presence of both a template DNA and a mixture of IDed
nanostructures, wherein each IDed nanostructure is associated with
a unique code and a unique combination of two or three consecutive
nucleotides. As shown in FIG. 6, a set of IDed nanostructures can
be used and each represents a unique combination of nucleotides. By
paring with the template DNA, the primer is extended with the
combination of nucleotides on the IDed nanostructures, whose coding
signal then identifies the unique combination, and hence the
sequence of the template DNA.
[0138] Another aspect of the present disclosure relates to methods
of detecting a condition in a sample or a subject, comprising:
hybridizing a DNA fragment from the sample or the subject with the
composition associated with a nucleic acid, and detecting the
presence of double stranded DNA in the IDed nanostructure which
indicates the presence of a condition in the sample or subject. In
certain embodiments, the nucleic acid comprises a known mutation
which is associated with the condition. For example, the presence
of the mutation may indicate presence of the condition in the
sample or the subject, or vice versa. The nucleic acid can be
designed to selectively pair with a DNA containing the mutation but
not with a DNA lacking the mutation, under a proper temperature
range. When subject to an endonuclease, the unpaired sample DNA
lacking the mutation, and also the unpaired nucleic acid on the
nanostructure would be digested. Alternatively or additionally, a
double stranded DNA dye may be used to detect the presence of the
double stranded hybridization product.
[0139] Another aspect of the present disclosure relates to methods
of detecting a condition in a sample or a subject, comprising:
hybridizing a DNA fragment from the sample or the subject with the
composition associated with a nucleic acid in a solution, adding a
single-stranded endonuclease into the solution, subjecting the
solution to a magnetic field, and detecting the presence or coding
signal of IDed nanostructure which indicates the presence of a
condition in the sample or subject. In certain embodiments, one end
of the nucleic acid is associated with a magnetic particle, and the
other end of the nucleic acid is associated with an IDed porous
nanostructure. The nucleic acid may further comprise a known
mutation which is associated with the condition, and can be
designed to indicate presence of the mutation in a sample DNA by
selectively pairing with the sample DNA with (or without) the
mutation. After the hybridization, the endonuclease would digest
the unpaired nucleic acid on the IDed nanostructure, thereby
separating the magnetic particle and the IDed nanostructure. When
subject to a magnetic field, the magnetic particles, associated
with or without the nucleic acid on the IDed nanostructure would be
separated, and detection of the presence of coding signal of the
IDed nanostructure would indicate pairing of the nucleic acid with
the sample DNA, and thereby indicating the presence or absence of
the mutation and of the condition of concern.
[0140] Another aspect of the present disclosure relates to methods
of detecting interaction of a nucleic acid with a testing agent,
wherein the nucleic acid is associated with a first IDed porous
nanostructure nanostructure having a first coding signal, and the
testing agent is associated with a second IDed porous nanostructure
having a second coding signal. The methods comprise contacting the
first IDed porous nanostructure with the second IDed porous
nanostructure, and detecting the interaction of the first and the
second coding signals. For example, if the nucleic acid binds to
the testing agent, then co-localization of the first and the second
coding signals can be detected. The testing agent can be any
suitable biological or chemical agents, for example, nucleic acids,
proteins, peptides, aptamers, chemical compounds, antibodies, and
etc. In certain embodiments, the first and the second IDed porous
nanostructures are contacted in a solution. In certain embodiments,
the methods further comprise assembling the first and the second
IDed porous nanostructures from the solution to a surface (e.g. by
using a magnetic grid, a magnet, etc.).
[0141] In certain embodiments, the nanostructure provided herein
can be used in the manufacture of therapeutic or diagnostic
compositions.
[0142] In certain embodiments, the nanostructure may be used to
deliver one or more therapeutic agents. For example, the
nanostructure may be used to provide for desired delivery (e.g.
targeted delivery) and/or desired release (e.g. extended and/or
controlled release) of the therapeutic agent(s). The nanostructure
may be delivered to a subject via a suitable route (e.g.,
intravenous, intraperitoneal, intramuscular, intradermal,
subcutaneous, transdermal, subdermal, intracranial, intranasal,
mucosal, anal, vaginal, oral, sublingual, buccal, or nasal). The
nanostructure suitable for therapeutic use may comprise one or more
therapeutic agent, either as an associated payload, or as a
conjugated molecule (e.g. a prodrug). Optionally, for target
delivery, the nanostructure may further comprise a targeting
moiety.
[0143] The nanostructure may also be used on samples (e.g. in vitro
or ex vivo) for diagnostic use. For example, the nanostructure may
be applied to or contacted with a sample under a suitable condition
that allows an expected reaction (e.g. hybridization,
amplification, affinity binding, staining, etc.) with its target
molecule suspected of being present in the sample (e.g. a biomarker
for a condition, a marker antigen, a pathogen, and/or a virus gene
sequence). The presence and/or extent of the reaction may be
detected or measured, so as to provide for information of presence
or absence of the target molecule, and/or the amount (e.g.
concentration) of such target molecule. The nanostructures useful
in such diagnostic use may comprise an agent capable of reacting
with the interested target molecule. Such agent can be a binding
partner such as antibody, antigen, aptamer, nucleic acid, probe,
chemical or other suitable agents. Such agent may be associated
with the nanostructure as a payload and/or be conjugated to the
nanostructure. Optionally, the nanostructure may further comprise a
detectable label that allows detection of the reaction.
[0144] In certain embodiments, the nanostructure provided herein
can be used in the manufacture of reagents useful in a qualitative
or quantitative test. For example, the nanostructure may be used to
contact an analyte and to allow identification and/or
quantification of the analyte. The analyte may be any substance
that can be detected, such as chemicals, explosives (e.g. TNT),
drugs (e.g. cocaine, heroin, cannabis, etc.), hazardous substances,
metal ions (e.g. heavy metal ions), contaminants, organic
compounds, alcohol, anabolic steroids, protons, nitric monoxide,
blood sugar, and metabolites etc. The analyte may be in any
suitable sample form, such as for example, in a biological specimen
(e.g. urine, sweat, breath, hair, saliva, and blood), in an
environmental specimen (e.g. river water, soil, and air), or in a
lab sample (e.g. dissolved in a lab buffer). The nanostructure
suitable for such analytic use may comprise a detecting agent (e.g.
as a payload or as a conjugate molecule) that allows identification
and/or quantification of the analyte, and such detecting agent can
be appropriately selected by people in the art based on the known
detection methods for the analyte.
[0145] In certain embodiments, the nanostructure provided herein
can be used in the manufacture of reagents useful in molecular
imaging. For example, the nanostructure provided herein may be
administered in vivo or in vitro to a subject (e.g., a mammal, a
human or other animals) via a suitable route (e.g. intravenously,
intra-arterially, orally, dermal application, subcutaneously,
intramuscular, intraperitoneal), followed by image generation of
the subject using a suitable device, such as an X-ray device, an
MRI device, a CT device, or devices for optical imaging, optical
coherence tomography, computed tomography, or positron emission
tomography. The generated images may be further analyzed to provide
distribution of the administered nanostructures in the subject, or
in an interested tissue, organ or compartment of the subject. The
nanostructure useful in molecular imaging may carry or be
associated with a payload comprising a fluorescent molecule, a
bioluminescent molecule, a radio isotope and/or other agents as a
suitable imaging or contract agent (A review on molecular imaging
can be found at: Weissleder, R. et al, Radiology, 219: 316-333
(2001)).
[0146] In certain embodiments, the nanostructure provided herein
can be used in the manufacture of reagents useful in separation,
purification or enrichment. For example, the nanostructure may be
used to contact a mixture which contains a component for which a
separation/purification/enrichment is interested. The interested
component may be, for example, a cell (e.g. tumor cell, a cell
expressing a specific marker antigen), a protein (e.g. antibody,
antibody fragment, antigen etc.), a nucleic acid, and a chemical
compound etc. The mixture may be or be derived from, for example, a
biological specimen (e.g. blood, serum, plasma, urine, tissue, cell
extract, cell lysate), a synthesized chemical product, an extract
of herbs or plants, and etc. The nanostructure comprises one or
more capturing agents that have an affinity to the interested
component. For example, the nanostructure may carry or be
conjugated with, for example, an antigen, antibody, complementary
nucleic acid, aptamer, and any other suitable binding partners. The
nanostructure with the interested component captured thereon, may
be separated from the remnants of the mixture using any suitable
separation methods, such as for example, by filtration,
centrifugation, chromatography (e.g. size-exclusion
chromatography), application of magnetic field (e.g. for
nanostructures comprising magnetic nanoparticles), or application
of electrical field. Optionally, the capture of the interested
component by the nanostructure is reversible, so that the component
may be released from the nanostructure after the
separation/purification/enrichment.
[0147] In certain embodiments, the nanostructure provided herein
can be used in the manufacture of semiconductors. Such
semiconductors may be used in light emitting devices,
optoelectronic devices, fluorescent label, electrodes, photovoltaic
cells, optical sensors, and biosensors etc. Some of these
applications are described in detail in Schmid, G. et al.,
Nanoparticles: From Theory to Application, published by John Wiley
& Sons, 2011.
EXAMPLES
Example 1
Preparation of Nanoparticles of Gold and Semiconductor Quantum Dots
with the Low Density Siliceous Structure
[0148] The low density siliceous structure is a versatile and
flexible platform for making biocompatible nanoparticles. For
example, to incorporate gold nanoparticles into the siliceous
structure, Au nanoparticles synthesized in either water solution or
organic solutions could be utilized. Briefly, Au was precipitated
out at the sample vial bottom after centrifuge at 13 k rpm for 15
min, then silane molecules such as aminopropyltrimethoxysilane and
TMAOH was added. The reaction solvent was adjusted using a higher
number alcohol, such as butanol or proponol. Then the sample was
sonicated for a few hours with constant blowing of air bubbles,
afterwards, PEG-silane, mercaptopropyltrimethoxysilane and
aminopropyltrimethoxysilane were added, the sample was sonicated
for additional 2-3 hours. Afterwards, mixture of
chlorotrimethylsilane, methanol, and TMAOH or other silane
molecules that only have one alkoxyl group connecting with the
silicon atom were added to react with surface siloxyl groups
presented on the surface of the already grown siliceous structure.
After additional sonicating and aging, stable nanoparticles with
the highly porous siliceous structure were collected and stored
within physiological buffer solutions through centrifugal
filtering, centrifugation, dialysis or any other solution exchange
methods. The resulting Au nanostructure was observed under TEM, and
an exemplary TEM image was shown in FIG. 2. The nanoparticle core
size was about 20 nm and hydrodynamic size was about 60 nm. The
siliceous coating was not obvious from the TEM.
Example 2
Preparation of Nanoparticles of Semiconductor Quantum Dots with the
Low Density Siliceous Structure
[0149] As another example, semiconductor quantum dots in the form
of individual nanocrystal or nanocrystal clusters could also be
incorporated within the highly porous/low density siliceous
structure. For example, CdSe/ZnS nanoparticles in organic solvents
such as chloroform, Toluene, or Hexane could be precipitated out by
adding methanol and then through centrifugation. The nanocrystal
pellet was then re-dispersed in aminopropyltrimethoxysilane or
mercaptopropyltrimethoxysilane. Afterwards, tetramethyl ammonium
hydroxide was added. Then the reaction solvent was adjusted using a
higher number alcohol, such as butanol or proponol. After
sonicating the sample for 1-4 hours and blowing air bubbles, small
amount of aminopropyltrimethoxysilane,
mercaptopropyltrimethoxysilane, polyethyleneoxidesilane and water
was subsequently added, and the sample then underwent sonication
for another 1 to 4 hours. Then, mixture of chlorotrimethylsilane,
methanol, and TMAOH or other silane molecules that only have one
alkoxyl group connecting with the silicon atom were added. This
sample was then sonicated for another 1-4 hours, followed by
overnight aging under mild shaking or vibration. The resulting
nanoparticles with low density/highly porous siliceous structure
were transferred into physiological buffer solutions by centrifugal
filtering, centrifugation, dialysis or any other solution exchange
methods. The resulting CdSe/ZnS nanostructure was observed under
TEM, and an exemplary TEM image was shown in FIG. 3. The
nanoparticle core size was about 10 nm and hydrodynamic size was
about 200 nm. The siliceous coating was not obvious from the
TEM.
Example 3
Preparation and Characterization of Low Density Magnetic
Particles
[0150] Preparation of the Magnetic Porous Nanostructure:
[0151] Magnetic particles formed by clustering multiple small
particles and then being coated were prepared. The clustering
happened with the addition of a worse solvent for generating
dispersed nanoparticles, such as butanol or isopropanol, followed
by the addition of the silanization reagents to form the
nanostructure under constant blowing of air bubbles. The magnetic
nanostructure as prepared were observed under TEM (FIG. 5). As
shown in FIG. 5, each large core nanoparticle comprised a cluster
of small nanoparticles, and the coating was substantially invisible
under TEM.
[0152] Characterization of Density of the Coating:
[0153] To calculate the density of the coating, both the dry mass
and the volume of the coating were characterized.
[0154] Since the magnetic particles had high magnetic response that
they could be directly captured using a magnet. This allowed
generation of dry particles to measure the mass of the material.
The dry mass of particles before and after coating was quantified
as follows. 200 ul of the coated particle solution was pipetted out
into a centrifugal vial whose mass was pre-measured. Coated
magnetic nanoparticles were captured to the side of the vial wall,
and the supernatant was removed. The captured particles were washed
with water. At the end, the particles absorbed to the side wall
were left to dry in the open vial under a fume hood. The mass of
the vial with the dry coated particles were measured. The dry
coated particle mass was calculated by subtraction of the mass of
the vial from the mass of the vial with the dry coated particles
inside. To measure the mass of the particles before coating,
uncoated particles corresponding to the same amount of the magnetic
material as in the coated nanoparticles, assuming an 80% coating
processing yield, was captured to the side of the vial, and dried.
The dry mass of the particles before coating was measured by
subtraction of the mass of the vial from the mass of the vial with
the dry uncoated particles inside. The mass of the coating was
equal to the mass of the dry coated particles minus the dry mass of
particles before coating.
TABLE-US-00001 TABLE 1 Average Core mass (n = 3) 0.67 mg Average
Coating mass (n = 3) 0.06 mg
[0155] The total volume of the coating was calculated using the
number of large particles in the above mass multiplied by the
volume of the coating of each individual large nanoparticles. The
particles were suspended in an aqueous solution, and the volume of
the coating of each large particle was calculated as
4/3.times..pi.(R.sup.3.sub.with coating-R.sup.3.sub.core), in which
the R.sub.with coating of an individual large nanoparticle was
measured using core with coating dynamic light scattering (DLS)
technique, and the R.sub.core of the large core particle was
directly imaged and measured using TEM (see FIG. 5).
TABLE-US-00002 TABLE 2 Average size of large core nanoparticles 210
nm under TEM Average size of coated large 217-357 nm nanoparticles
under DLS Average coating volume of an coated 4/3 .times. .pi.
(110.sup.3 - 105.sup.3) nm.sup.3 large nanoparticle
[0156] The number of large particles in the mass was calculated by
dividing the total number of small nanoparticles by the number of
small nanoparticles in each large nanoparticle. The total number of
small nanoparticles was estimated by dividing the mass of total
magnetic material by the mass of an individual small nanoparticle
(i.e. calculated using the size and density of the small
nanoparticle). The number of small nanoparticles in each individual
large particle was counted from the TEM micrograph. Hence, the
total volume of the coating can be calculated as the volume of
coating of a large nanoparticle multiplied by the total number of
the large nanoparticles.
TABLE-US-00003 TABLE 3 Core mass 0.67 mg Density of core 5.2
kg/m.sup.3 Small nanoparticle size 16 nm Small nanoparticle Volume
2.1 .times. 10.sup.-24 m.sup.3 Mass of each small narnoparticle 1.1
.times. 10.sup.-17 mg Number of small particles in the core 6.1
.times. 10.sup.16 Average number of small particle per large
particle 236 Number of large particles in the core 2.6 .times.
10.sup.14 Total volume of the coating 4/3 .times. .pi. (110.sup.3 -
105.sup.3) nm.sup.3 .times. 2.6 .times. 10.sup.14 = 0.1875 .times.
10.sup.-6 m.sup.3.
[0157] The density of the coating was calculated using the mass of
the coating divided by the total volume of the coating, i.e., 0.06
mg/0.1875.times.10.sup.-6 m.sup.3=0.32 mg/cm.sup.3.
[0158] The density of the low density siliceous structure prepared
herein is only 0.32 mg/cm.sup.3, which is significantly lower than
the density of some reported silica coatings, for example, those
reported in Vincent et al (Vincent, A. et al, J. Phys. Chem. C
2007, 111, 8291-8298), that have a density of 1-2 g/cc and are
10.sup.4 denser than the siliceous structure provided herein.
[0159] Characterization of Porosity Using BET Method:
[0160] Large magnetic nanoparticles after coating were captured to
the side of the vial and dried. 2 samples of 65 mg (sample 1) and
45 mg (sample 2) dry mass were prepared for the BET
measurement.
[0161] Surface pore sizes were measured using BET method for the
dry mass of the coated nanoparticles. The results are shown in the
below Tables.
TABLE-US-00004 TABLE 4 Characterization for Sample 1 Surface Area
14.166 m.sup.2/g Total pore volume for pores 7.562 .times.
10.sup.-2 cc/g smaller than 677.5 .ANG. (Radius) at P/P.sub.0 =
0.98562
TABLE-US-00005 TABLE 5 Characterization for Sample 2 Surface Area
6.380 m.sup.2/g Total pore volume for pores 7.099 .times. 10.sup.-2
cc/g smaller than 683.3 .ANG. (Radius) at P/Po = 0.98575
[0162] The surface area and the pore volume of the porous
nanostructure were measured with dry mass of the porous
nanostructure. If measured with a nanostructure sample suspended in
an aqueous solution, the pore volume and the surface area are
expected to be much higher than the measurements with the dry mass,
as the density of the coating has been shown to be at least
10.sup.4 lower than those reported in the art.
[0163] The measured density based on the dry power samples does not
reflect the real density of the 3-D structure because of the
ultralow density of the 3-D structure, the framework easily
collapses during the drying process, hence providing much smaller
numbers in the porosity measurement than when the 3-D structure is
fully extended, for example, like when the porous nanostructure is
fully extended in a buffer solution.
Example 4
Preparation and Characterization of IDed Nanostructure
[0164] Preparation of IDed Magnetic Nanostructure.
[0165] The IDed fluorescent magnetic nanoparticles were prepared by
incorporating both magnetic nanoparticles and fluorescent
particles, such as organic fluorophores or organically soluble
quantum dots into the porous nanostructure formulation process,
where each individual component, i.e., magnetic or fluorescent was
associated with the porous matrix through covalent binding or
non-covalent interaction, such as metal-ligand chelating,
hydrophobic or electrostatic association. The different IDed
nanostructures were dispersed in a buffer, and an image under
fluorescent microscope showed the different colors of the IDed
nanostructures (see FIG. 9).
[0166] Conjugation of the IDed Nanostructures.
[0167] The IDed nanostructures were first conjugated with
streptavidin through covalent binding of amine groups of
streptavidin to mercapto groups on the surface of IDed
nanostructures. After streptavidin conjugation, each type of the
IDed magnetic nanostructures was magnetically purified, and
redispersed in a separate buffer solution.
[0168] A sense DNA strand and its antisense DNA strand, both
biotinylated, were commercially obtained. To allow conjugation of
the IDed nanostructure to the corresponding biotinylated DNA, the
red IDed nanostructure was mixed with biotin-sense DNA, and the
green IDed nanostructure was mixed with biotin-antisense DNA. The
ratio of biotin-DNA to the IDed nanostructures could be ranged from
1 to 100. The conjugation were performed under room temperature in
an appropriate buffer under continuous rotating, and incubated for
1 to 4 hours. Each of the IDed nanostructure-DNA conjugates was
purified using a magnet, and washed once with buffer. Afterwards,
the IDed nanostructure-sense DNA and IDed nanostructure-antisense
DNA were mixed together for the hybridization reaction, and left on
a rotator overnight.
[0169] On the second day, an aliquot of solution was taken out of
the hybridization solution and observed under microscope. Images
from the hybridized sample solution were compared with images from
the control sample, where the same quantity of the same two types
of IDed nanoparticle-streptavidin conjugates without DNA oligomer
were mixed together and incubated overnight. Results were shown in
FIG. 11 (a) (control sample), and FIG. 11 (b)-(m) (DNA
hybridization sample). As shown in the results, DNA hybridization
was manifested as co-localization of both the red and green IDed
nanostructures.
[0170] A magnetic grid can also be used to facilitate the
detection. After hybridization of the IDed nanostructure-sense DNA
and IDed nanostructure-antisense DNA, a magnetic grid was placed
onto a surface of a flow cell, the hybridization sample was allowed
to flow through the surface of the magnetic grid, and captured by
the magnetic grid. This method allowed the hybridization reaction
to happen in a solution, while the detection can be conducted on a
surface. Images from the hybridized sample solution were compared
with images from the control sample with the magnetic grid. Results
were shown in FIG. 12 (a) (control sample) and FIG. 12 (b) (DNA
hybridization sample). As shown in the results, DNA hybridization
was manifested as co-localization of both the red and green IDed
nanostructures on the magnetic grid. No obvious co-localization of
the two IDed nanostructures was observed.
* * * * *